Substituted hydroxamic acids and uses thereof

ABSTRACT

This invention provides compounds of formula (I): 
     
       
         
         
             
             
         
       
         
         
           
             wherein R 1a , R 1b , R a , R 2a , R 2b , R 1 , and X have values as described in the specification, useful as inhibitors of HDAC6. The invention also provides pharmaceutical compositions comprising the compounds of the invention and methods of using the compositions in the treatment of proliferative, inflammatory, infectious, neurological or cardiovascular diseases or disorders.

PRIORITY CLAIM

This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application Ser. No. 61/393,967, filed Oct. 18, 2010, incorporated by reference in its entirety, and U.S. Provisional Patent Application Ser. No. 61/426,418, filed Dec. 22, 2010, incorporated by reference in its entirety.

FIELD OF THE INVENTION

The invention relates to compounds and methods for the selective inhibition of HDAC6. The present invention relates to compounds useful as HDAC6 inhibitors. The invention also provides pharmaceutical compositions comprising the compounds of the invention and methods of using the compositions in the treatment of various diseases.

BACKGROUND OF THE INVENTION

Histone deacetylase 6 (HDAC6) is a member of a family of amidohydrolases commonly referred as histone or lysine deacetylases (HDACs or KDACs) as they catalyze the removal of acetyl groups from the ε-amino group of lysine residues from proteins. The family includes 18 enzymes which can be divided in 3 main classes based on their sequence homology to yeast enzymes Rpd3 (Class I), Hda1 (Class II) and Sir2 (Class III). A fourth class was defined with the finding of a distinct mammalian enzyme—HDAC11 (reviewed in Yang, et al., Nature Rev. Mol. Cell. Biol. 2008, 9:206-218 and in Saunders and Verdin, Oncogene 2007, 26(37):5489-5504). Biochemically, Class I (HDAC1, 2, 3, 8) and Class II (HDAC4, 5, 6, 7, 9, 10) and Class IV (HDAC11) are Zn²⁺-dependent enzymes, while Class III (SIRT1-7) are dependent on nicotinamide adenine dinucleotide (NAD⁺) for activity. Unlike all other HDACs, HDAC6 resides primarily in the cytosol. It has 2 functional catalytic domains and a carboxy-terminal Zn²⁺-finger ubiquitin binding domain that binds ubiquitinated misfolded proteins (Kawaguchi et al., Cell 2003, 115(6):727-738), ubiquitin (Boyaullt et al., EMBO J. 2006, 25(14): 3357-3366), as well as ubiquitin-like FAT10 modifier (Kalveram et al., J. Cell Sci. 2008, 121(24):4079-4088). Known substrates of HDAC6 include cytoskeletal proteins α-tubulin and cortactin; β-catenin which forms part of adherens junctions and anchors the actin cytoskeleton; the chaperone Hsp90; and the redox regulatory proteins peroxiredoxin (Prx) I and Prx II (reviewed in Boyault et al., Oncogene 2007, 26(37):5468-5476; Matthias et al., Cell Cycle 2008, 7(1):7-10; Li et al., J Biol. Chem. 2008, 283(19):12686-12690; Parmigiani et al., Proc. Natl. Acad. Sci. USA 2009, 105(28):9633-9638). Thus, HDAC6 mediates a wide range of cellular functions including microtubule-dependent trafficking and signaling, membrane remodeling and chemotactic motility, involvement in control of cellular adhesion, ubiquitin level sensing, regulation of chaperone levels and activity, and responses to oxidative stress. All of these functions may be important in tumorigenesis, tumor growth and survival as well as metastasis (Simms-Waldrip et al., Mol. Genet. Metabolism 2008, 94(3):283-286; Rodriguez-Gonzalez et al., Cancer Res. 2008, 68(8):2557-2560; Kapoor, Int. J. Cancer 2009, 124:509; Lee et al., Cancer Res. 2008, 68(18):7561-7569). Recent studies have shown HDAC6 to be important in autophagy, an alternative pathway for protein degradation that compensates for deficiencies in the activity of the ubiquitin proteasome system or expression of proteins prone to form aggregates and can be activated following treatment with a proteasome inhibitor (Kawaguchi et al., Cell 2003, 115(6):727-738; Iwata et al., J. Biol. Chem. 2005, 280(48): 40282-40292; Ding et al., Am. J. Pathol. 2007, 171:513-524, Pandey et al., Nature 2007, 447(7146):860-864). Although the molecular mechanistic details are not completely understood, HDAC6 binds ubiquitinated or ubiquitin-like conjugated misfolded proteins which would otherwise induce proteotoxic stress and then serves as an adaptor protein to traffic the ubiquitinated cargo to the microtubule organizing center using the microtubule network via its known association with dynein motor protein. The resulting perinuclear aggregates, known as aggresomes, are then degraded by fusion with lysosomes in an HDAC6- and cortactin-dependent process which induces remodeling of the actin cytoskeleton proximal to aggresomes (Lee et al., EMBO J. 2010, 29:969-980). In addition, HDAC6 regulates a variety of biological processes dependent on its association with the microtubular network including cellular adhesion (Tran et al., J. Cell Sci. 2007, 120(8):1469-1479) and migration (Zhang et al., Mol. Cell. 2007, 27(2):197-213; reviewed in Valenzuela-Fernandez et al., Trends Cell. Biol. 2008, 18(6):291-297), epithelial to mesenchymal transition (Shan et al., J. Biol. Chem. 2008, 283(30):21065-21073), resistance to anoikis (Lee et al., Cancer Res. 2008, 68(18):7561-7569), epithelial growth factor-mediated Wnt signaling via β-catenin deacetylation (Li et al., J. Biol. Chem. 2008, 283(19):12686-12690) and epithelial growth factor receptor stabilization by endocytic trafficking (Lissanu Deribe et al., Sci. Signal. 2009, 2(102): ra84; Gao et al., J. Biol. Chem. 2010, 285:11219-11226); all events that promote oncogenesis and metastasis (Lee et al., Cancer Res. 2008, 68(18):7561-7569). HDAC6 activity is known to be upregulated by Aurora A kinase in cilia formation (Pugacheva et al., Cell 2007, 129(7):1351-1363) and indirectly by farnesyl transferase with which HDAC6 forms a complex with microtubules (Zhou et al., J. Biol. Chem. 2009, 284(15): 9648-9655). Also, HDAC6 is negatively regulated by tau protein (Perez et al., J. Neurochem. 2009, 109(6):1756-1766).

Diseases in which selective HDAC6 inhibition could have a potential benefit include cancer (reviewed in Simms-Waldrip et al., Mol. Genet. Metabolism 2008, 94(3):283-286 and Rodriguez-Gonzalez et al., Cancer Res. 2008, 68(8):2557-2560), specifically: multiple myeloma (Hideshima et al., Proc. Natl. Acad. Sci. USA 2005, 102(24):8567-8572); lung cancer (Kamemura et al., Biochem. Biophys. Res. Commun. 2008, 374(1):84-89); ovarian cancer (Bazzaro et al., Clin. Cancer Res. 2008, 14(22):7340-7347); breast cancer (Lee et al., Cancer Res. 2008, 68(18):7561-7569); prostate cancer (Mellado et al., Clin. Trans. Onco. 2009, 11(1):5-10); pancreatic cancer (Nawrocki et al., Cancer Res. 2006, 66(7):3773-3781); renal cancer (Cha et al., Clin. Cancer Res. 2009, 15(3):840-850); and leukemias such as acute myeloid leukemia (AML) (Fiskus et al., Blood 2008, 112(7):2896-2905) and acute lymphoblastic leukemia (ALL) (Rodriguez-Gonzalez et al., Blood 2008, 112(11): Abstract 1923).

Inhibition of HDAC6 may also have a role in cardiovascular disease, i.e. cardiovascular stress, including pressure overload, chronic ischemia, and infarction-reperfusion injury (Tannous et al., Circulation 2008, 117(24):3070-3078); bacterial infection, including those caused by uropathogenic Escherichia coli (Dhakal and Mulve, J. Biol. Chem. 2008, 284(1):446-454); neurological diseases caused by accumulation of intracellular protein aggregates such as Huntington's disease (reviewed in Kazantsev et al., Nat. Rev. Drug Disc. 2008, 7(10):854-868; see also Dompierre et al., J. Neurosci. 2007, 27(13):3571-3583; Kozikowski et al., J. Med. Chem. 2007, 50:3054-3061) or central nervous system trauma caused by tissue injury, oxidative-stress induced neuronal or axomal degeneration (Rivieccio et al., Proc. Natl. Acad. Sci. USA 2009, 106(46):19599-195604); and inflammation, including reduction of pro-inflammatory cytokine IL-1β (Carta et al., Blood 2006, 108(5):1618-1626), increased expression of the FOXP3 transcription factor, which induces immunosuppressive function of regulatory T-cells resulting in benefits in chronic diseases such as rheumatoid arthritis, psoriasis, multiple sclerosis, lupus and organ transplant rejection (reviewed in Wang et al., Nat. Rev. Drug Disc. 2009, 8(12):969-981).

Given the complex function of HDAC6, selective inhibitors could have potential utility when used alone or in combination with other chemotherapeutics such as microtubule destabilizing agents (Zhou et al., J. Biol. Chem. 2009, 284(15): 9648-9655); Hsp90 inhibitors (Rao et al., Blood 2008, 112(5)1886-1893); inhibitors of Hsp90 client proteins, including receptor tyrosine kinases such as Her-2 or VEGFR (Bhalla et al., J. Clin. Oncol. 2006, 24(18S): Abstract 1923; Park et al., Biochem. Biophys. Res. Commun. 2008, 368(2):318-322), and signaling kinases such as Bcr-Abl, Akt, mutant FLT-3, c-Raf, and MEK (Bhalla et al., J. Clin. Oncol. 2006, 24(18S): Abstract 1923; Kamemura et al., Biochem. Biophys. Res. Commun. 2008, 374(1):84-89); inhibitors of cell cycle kinases Aurora A and Aurora B (Pugacheva et al., Cell 2007, 129(7):1351-1363; Park et al., J. Mol. Med. 2008, 86(1):117-128; Cha et al., Clin. Cancer Res. 2009, 15(3):840-850); EGFR inhibitors (Lissanu Deribe et al., Sci. Signal. 2009, 2(102): ra84; Gao et al., J. Biol. Chem. 2010, 285:11219-11226) and proteasome inhibitors (Hideshima et al., Proc. Natl. Acad. Sci. USA 2005, 102(24):8567-8572) or other inhibitors of the ubiquitin proteasome system such as ubiquitin and ubiqutin-like activating (E1), conjugation (E2), ligase enzymes (E3, E4) and deubiquitinase enzymes (DUBs) as well as modulators of autophagy and protein homeostasis pathways. In addition, HDAC6 inhibitors could be combined with radiation therapy (Kim et al., Radiother. Oncol. 2009, 92(1):125-132.

Clearly, it would be beneficial to provide novel HDAC6 inhibitors that possess good therapeutic properties, especially for the treatment of proliferative diseases or disorders.

DETAILED DESCRIPTION OF THE INVENTION 1. General Description of Compounds of the Invention

The present invention provides compounds that are effective inhibitors of HDAC6. These compounds are useful for inhibiting HDAC6 activity in vitro and in vivo, and are especially useful for the treatment of various cell proliferative diseases or disorders. The compounds of the invention are represented by formula (I):

or a pharmaceutically acceptable salt thereof;

wherein:

each occurrence of R¹ is independently hydrogen, chloro, fluoro, —O—C₁₋₄ alkyl, cyano, hydroxy, C₁₋₄ alkyl, or C₁₋₄ fluoroalkyl;

one of R^(2a) and R^(2b) is R¹, and the other is —C(O)—NH—OH;

X is C(R^(1c))(R^(1d)) or N—R^(b);

R^(1d) is taken together with R^(1b) to form a double bond;

R^(1c) is hydrogen, fluoro, bromo, —CH₂—OR^(4aa), —CH₂N(R^(4aa))₂, or C₁₋₄ alkyl;

-   -   R^(b) is hydrogen, C₁₋₆ alkyl, benzyl, or phenyl; or R^(b) is         taken together with R^(1b) to form a double bond;

when X is C(R^(1c))(R^(1d)), R^(1b) is taken together with R^(1d) to form a double bond; and when X is N—R^(b), R^(1b) is taken together with R^(b) to form a double bond, or is taken together with R^(a) to form a double bond, or is taken together with R^(1a) to form C═O;

R^(1a) is hydrogen, fluoro, C₁₋₄ alkyl, C₁₋₄ fluoroalkyl, or G¹; or when X is N—R^(b), R^(1a) can be taken together with R^(1b) to form C═O;

R^(a) is hydrogen, C₁₋₄ alkyl, or G; or when X is N—R^(b), R^(1b) can be taken together with R^(a) to form a double bond;

G is hydrogen, —R³, -L₁-R³, or -L₂-V₁—R³;

G¹ is —NH₂, —R³, -L₁-R³, —V₂—R³, -L₁-V₂—R³, or —V₂-L₁-R³;

V₁ is —O—, —N(R^(4a))—, —S—, —N(R^(4a))—C(O)—, —C(O)—N(R^(4a))—, —SO₂—N(R^(4a))—, —N(R^(4a))—SO₂—, —C(O)—, —SO₂—, or —N(R^(4a))—C(O)—N(R^(4a))—;

V₂ is —O—, —N(R^(4a))—, —C(O)—N(R^(4a))—, —N(R^(4a))—C(O)—N(R^(4a))—, or —N(R^(4a))—C(O)—O—;

L₁ is an unsubstituted or substituted C₁₋₄ alkylene chain;

L₂ is an unsubstituted or substituted C₂₋₄ alkylene chain;

each occurrence of R^(4aa) is independently hydrogen or C₁₋₄ alkyl;

R³ is unsubstituted or substituted C₁₋₆ aliphatic, unsubstituted or substituted 3-10-membered cycloaliphatic, unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur; and

each occurrence of R^(4a) is independently hydrogen, unsubstituted or substituted C₁₋₄ aliphatic, unsubstituted or substituted 3-10-membered cycloaliphatic, unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur.

2. Compounds and Definitions

Compounds of this invention include those described generally for formula (I) above, and are further illustrated by the classes, subclasses, and species disclosed herein. As used herein, the following definitions shall apply unless otherwise indicated.

As described herein, compounds of the invention may be optionally substituted with one or more substituents, such as are illustrated generally above, or as exemplified by particular classes, subclasses, and species of the invention. It will be appreciated that the phrase “optionally substituted” is used interchangeably with the phrase “substituted or unsubstituted.” In general, the term “substituted”, whether preceded by the term “optionally” or not, means that a hydrogen radical of the designated moiety is replaced with the radical of a specified substituent, provided that the substitution results in a stable or chemically feasible compound. The term “substitutable”, when used in reference to a designated atom, means that attached to the atom is a hydrogen radical, which hydrogen atom can be replaced with the radical of a suitable substituent. Unless otherwise indicated, an “optionally substituted” group may have a substituent at each substitutable position of the group, and when more than one position in any given structure may be substituted with more than one substituent selected from a specified group, the substituent may be either the same or different at every position. Combinations of substituents envisioned by this invention are preferably those that result in the formation of stable or chemically feasible compounds.

A stable compound or chemically feasible compound is one in which the chemical structure is not substantially altered when kept at a temperature from about −80° C. to about +40° C., in the absence of moisture or other chemically reactive conditions, for at least a week, or a compound which maintains its integrity long enough to be useful for therapeutic or prophylactic administration to a patient.

The phrase “one or more substituents”, as used herein, refers to a number of substituents that equals from one to the maximum number of substituents possible based on the number of available bonding sites, provided that the above conditions of stability and chemical feasibility are met.

As used herein, the term “independently selected” means that the same or different values may be selected for multiple instances of a given variable in a single compound.

As used herein, the term “aromatic” includes aryl and heteroaryl groups as described generally below and herein.

The term “aliphatic” or “aliphatic group”, as used herein, means an optionally substituted straight-chain or branched C₁₋₁₂ hydrocarbon. For example, suitable aliphatic groups include optionally substituted linear, or branched alkyl, alkenyl, alkynyl groups and hybrids thereof. Unless otherwise specified, in various embodiments, aliphatic groups have 1-12, 1-10, 1-8, 1-6, 1-4, 1-3, or 1-2 carbon atoms.

The term “alkyl”, used alone or as part of a larger moiety, refers to an optionally substituted straight or branched chain hydrocarbon group having 1-12, 1-10, 1-8, 1-6, 1-4, 1-3, or 1-2 carbon atoms.

The term “alkenyl”, used alone or as part of a larger moiety, refers to an optionally substituted straight or branched chain hydrocarbon group having at least one double bond and having 2-12, 2-10, 2-8, 2-6, 2-4, or 2-3 carbon atoms.

The term “alkynyl”, used alone or as part of a larger moiety, refers to an optionally substituted straight or branched chain hydrocarbon group having at least one triple bond and having 2-12, 2-10, 2-8, 2-6, 2-4, or 2-3 carbon atoms.

The terms “cycloaliphatic”, “carbocycle”, “carbocyclyl”, “carbocyclo”, or “carbocyclic”, used alone or as part of a larger moiety, refer to an optionally substituted saturated or partially unsaturated cyclic aliphatic ring system having from 3 to about 14 ring carbon atoms. In some embodiments, the cycloaliphatic group is an optionally substituted monocyclic hydrocarbon having 3-10, 3-8 or 3-6 ring carbon atoms. Cycloaliphatic groups include, without limitation, optionally substituted cyclopropyl, cyclobutyl, cyclopentyl, cyclopentenyl, cyclohexyl, cyclohexenyl, cycloheptyl, cycloheptenyl, cyclooctyl, cyclooctenyl, or cyclooctadienyl. The terms “cycloaliphatic”, “carbocycle”, “carbocyclyl”, “carbocyclo”, or “carbocyclic” also include optionally substituted bridged or fused bicyclic rings having 6-12, 6-10, or 6-8 ring carbon atoms, wherein any individual ring in the bicyclic system has 3-8 ring carbon atoms.

The term “cycloalkyl” refers to an optionally substituted saturated ring system of about 3 to about 10 ring carbon atoms. Exemplary monocyclic cycloalkyl rings include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl.

The term “cycloalkenyl” refers to an optionally substituted non-aromatic monocyclic or multicyclic ring system containing at least one carbon-carbon double bond and having about 3 to about 10 carbon atoms. Exemplary monocyclic cycloalkenyl rings include cyclopentenyl, cyclohexenyl, and cycloheptenyl.

The terms “haloaliphatic”, “haloalkyl”, “haloalkenyl” and “haloalkoxy” refer to an aliphatic, alkyl, alkenyl or alkoxy group, as the case may be, which is substituted with one or more halogen atoms. As used herein, the term “halogen” or “halo” means F, Cl, Br, or I. The term “fluoroaliphatic” refers to a haloaliphatic wherein the halogen is fluoro, including perfluorinated aliphatic groups. Examples of fluoroaliphatic groups include, without limitation, fluoromethyl, difluoromethyl, trifluoromethyl, 2-fluoroethyl, 2,2,2-trifluoroethyl, 1,1,2-trifluoroethyl, 1,2,2-trifluoroethyl, and pentafluoroethyl.

The term “heteroatom” refers to one or more of oxygen, sulfur, nitrogen, phosphorus, or silicon (including, any oxidized form of nitrogen, sulfur, phosphorus, or silicon; the quaternized form of any basic nitrogen or; a substitutable nitrogen of a heterocyclic ring, for example N (as in 3,4-dihydro-2H-pyrrolyl), NH (as in pyrrolidinyl) or NR+ (as in N-substituted pyrrolidinyl)).

The terms “aryl” and “ar-”, used alone or as part of a larger moiety, e.g., “aralkyl”, “aralkoxy”, or “aryloxyalkyl”, refer to an optionally substituted C₆₋₁₄ aromatic hydrocarbon moiety comprising one to three aromatic rings. Preferably, the aryl group is a C₆₋₁₀aryl group. Aryl groups include, without limitation, optionally substituted phenyl, naphthyl, or anthracenyl. The terms “aryl” and “ar-”, as used herein, also include groups in which an aryl ring is fused to one or more cycloaliphatic rings to form an optionally substituted cyclic structure such as a tetrahydronaphthyl, indenyl, or indanyl ring. The term “aryl” may be used interchangeably with the terms “aryl group”, “aryl ring”, and “aromatic ring”.

An “aralkyl” or “arylalkyl” group comprises an aryl group covalently attached to an alkyl group, either of which independently is optionally substituted. Preferably, the aralkyl group is C₆₋₁₀arylC₁₋₆alkyl, including, without limitation, benzyl, phenethyl, and naphthylmethyl.

The terms “heteroaryl” and “heteroar-”, used alone or as part of a larger moiety, e.g., “heteroaralkyl”, or “heteroaralkoxy”, refer to groups having 5 to 14 ring atoms, preferably 5, 6, 9, or 10 ring atoms; having 6, 10, or 14 π electrons shared in a cyclic array; and having, in addition to carbon atoms, from one to five heteroatoms. In some embodiments, the heteroaryl group has 5-10 ring atoms, having, in addition to carbon atoms, from one to five heteroatoms. A heteroaryl group may be mono-, bi-, tri-, or polycyclic, preferably mono-, bi-, or tricyclic, more preferably mono- or bicyclic. The term “heteroatom” refers to nitrogen, oxygen, or sulfur, and includes any oxidized form of nitrogen or sulfur, and any quaternized form of a basic nitrogen. For example, a nitrogen atom of a heteroaryl may be a basic nitrogen atom and may also be optionally oxidized to the corresponding N-oxide. When a heteroaryl is substituted by a hydroxy group, it also includes its corresponding tautomer. The terms “heteroaryl” and “heteroar-”, as used herein, also include groups in which a heteroaromatic ring is fused to one or more aryl, cycloaliphatic, or heterocycloaliphatic rings. Nonlimiting examples of heteroaryl groups include thienyl, furanyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, oxadiazolyl, thiazolyl, isothiazolyl, thiadiazolyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, indolizinyl, purinyl, naphthyridinyl, pteridinyl, indolyl, isoindolyl, benzothienyl, benzofuranyl, dibenzofuranyl, indazolyl, benzimidazolyl, benzthiazolyl, quinolyl, isoquinolyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, 4H-quinolizinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, and pyrido[2,3-b]-1,4-oxazin-3(4H)-one. The term “heteroaryl” may be used interchangeably with the terms “heteroaryl ring”, “heteroaryl group”, or “heteroaromatic”, any of which terms include rings that are optionally substituted. The term “heteroaralkyl” refers to an alkyl group substituted by a heteroaryl, wherein the alkyl and heteroaryl portions independently are optionally substituted.

As used herein, the terms “heterocycle”, “heterocyclyl”, “heterocyclic radical”, and “heterocyclic ring” are used interchangeably and refer to a stable 4-10 membered ring, preferably a 3- to 8-membered monocyclic or 7-10-membered bicyclic heterocyclic moiety that is either saturated or partially unsaturated, and having, in addition to carbon atoms, one or more, preferably one to four, heteroatoms, as defined above. When used in reference to a ring atom of a heterocycle, the term “nitrogen” includes a substituted nitrogen. As an example, in a saturated or partially unsaturated ring having 0-3 heteroatoms selected from oxygen, sulfur or nitrogen, the nitrogen may be N (as in 3,4-dihydro-2H-pyrrolyl), NH (as in pyrrolidinyl), or NR+ (as in N-substituted pyrrolidinyl).

A heterocyclic ring can be attached to its pendant group at any heteroatom or carbon atom that results in a stable structure and any of the ring atoms can be optionally substituted. Examples of such saturated or partially unsaturated heterocyclic radicals include, without limitation, tetrahydrofuranyl, tetrahydrothienyl, piperidinyl, decahydroquinolinyl, oxazolidinyl, piperazinyl, dioxanyl, dioxolanyl, diazepinyl, oxazepinyl, thiazepinyl, morpholinyl, and thiomorpholinyl. A heterocyclyl group may be mono-, bi-, tri-, or polycyclic, preferably mono-, bi-, or tricyclic, more preferably mono- or bicyclic. The term “heterocyclylalkyl” refers to an alkyl group substituted by a heterocyclyl, wherein the alkyl and heterocyclyl portions independently are optionally substituted. Additionally, a heterocyclic ring also includes groups in which the heterocyclic ring is fused to one or more aryl rings.

As used herein, the term “partially unsaturated” refers to a ring moiety that includes at least one double or triple bond between ring atoms. The term “partially unsaturated” is intended to encompass rings having multiple sites of unsaturation, but is not intended to include aromatic (e.g., aryl or heteroaryl) moieties, as herein defined.

The term “alkylene” refers to a bivalent alkyl group. An “alkylene chain” is a polymethylene group, i.e., —(CH₂)_(n)—, wherein n′ is a positive integer, preferably from 1 to 6, from 1 to 4, from 1 to 3, from 1 to 2, or from 2 to 3. An optionally substituted alkylene chain is a polymethylene group in which one or more methylene hydrogen atoms is optionally replaced with a substituent. Suitable substituents include those described below for a substituted aliphatic group and also include those described in the specification herein. It will be appreciated that two substituents of the alkylene group may be taken together to form a ring system. In certain embodiments, two substituents can be taken together to form a 3-7-membered ring. The substituents can be on the same or different atoms.

An alkylene chain also can be optionally interrupted by a functional group. An alkylene chain is “interrupted” by a functional group when an internal methylene unit is interrupted by the functional group. Examples of suitable “interrupting functional groups” are described in the specification and claims herein.

For purposes of clarity, all bivalent groups described herein, including, e.g., the alkylene chain linkers described above, are intended to be read from left to right, with a corresponding left-to-right reading of the formula or structure in which the variable appears.

An aryl (including aralkyl, aralkoxy, aryloxyalkyl and the like) or heteroaryl (including heteroaralkyl and heteroarylalkoxy and the like) group may contain one or more substituents and thus may be “optionally substituted”. In addition to the substituents defined above and herein, suitable substituents on the unsaturated carbon atom of an aryl or heteroaryl group also include and are generally selected from -halo, —NO₂, —CN, —R⁺, —C(R⁺)═C(R⁺)₂, —C≡C—R⁺, —OR⁺, —SR°, —S(O)R°, —SO₂R°, —SO₃R⁺, —SO₂N(R⁺)₂, —N(R⁺)₂, —NR⁺C(O)R⁺, —NR⁺C(S)R⁺, —NR⁺C(O)N(R⁺)₂, —NR⁺C(S)N(R⁺)₂, —N(R⁺)C(═NR⁺)—N(R⁺)₂, —N(R⁺)C(═NR⁺)—R°, —NR⁺CO₂R⁺, —NR⁺SO₂R°, —NR⁺SO₂N(R⁺)², —O—C(O)R⁺, —O—CO₂R⁺, —OC(O)N(R⁺)₂, —C(O)R⁺, —C(S)R°, —CO₂R⁺, —C(O)—C(O)R⁺, —C(O)N(R⁺)₂, —C(S)N(R⁺)₂, —C(O)N(R⁺)—OR⁺, —C(O)N(R⁺)C(═NR⁺)—N(R⁺)₂, —N(R⁺)C(═NR⁺)—N(R⁺)—C(O)R⁺, —C(═NR⁺)—N(R)₂, —C(═NR⁺)—OR⁺, —N(R⁺)—N(R⁺)₂, —C(═NR⁺)—N(R⁺)—OR⁺—C(R°)═N—OR⁺, —P(O)(R⁺)₂, —P(O)(OR⁺)₂, —O—P(O)—OR⁺, and —P(O)(NR⁺)—N(R⁺)₂, wherein R⁺, independently, is hydrogen or an optionally substituted aliphatic, aryl, heteroaryl, cycloaliphatic, or heterocyclyl group, or two independent occurrences of R⁺ are taken together with their intervening atom(s) to form an optionally substituted 5-7-membered aryl, heteroaryl, cycloaliphatic, or heterocyclyl ring. Each R° is an optionally substituted aliphatic, aryl, heteroaryl, cycloaliphatic, or heterocyclyl group.

An aliphatic or heteroaliphatic group, or a non-aromatic carbycyclic or heterocyclic ring may contain one or more substituents and thus may be “optionally substituted”. Unless otherwise defined above and herein, suitable substituents on the saturated carbon of an aliphatic or heteroaliphatic group, or of a non-aromatic carbocyclic or heterocyclic ring are selected from those listed above for the unsaturated carbon of an aryl or heteroaryl group and additionally include the following: ═O, ═S, ═C(R*)₂, ═N—N(R*)₂, ═N—OR*, ═N—NHC(O)R*, ═N—NHCO₂R°, ═N—NHSO₂R° or ═N—R* where R° is defined above, and each R* is independently selected from hydrogen or an optionally substituted C₁₋₆ aliphatic group.

In addition to the substituents defined above and herein, optional substituents on the nitrogen of a non-aromatic heterocyclic ring also include and are generally selected from —R⁺, —N(R⁺)₂, —C(O)R⁺, —C(O)OR⁺, —C(O)C(O)R⁺, —C(O)CH₂C(O)R⁺, —S(O)₂R⁺, —S(O)₂N(R⁺)₂, —C(S)N(R⁺)₂, —C(═NH)—N(R⁺)₂, or —N(R⁺)S(O)₂R⁺; wherein each R⁺ is defined above. A ring nitrogen atom of a heteroaryl or non-aromatic heterocyclic ring also may be oxidized to form the corresponding N-hydroxy or N-oxide compound. A nonlimiting example of such a heteroaryl having an oxidized ring nitrogen atom is N-oxidopyridyl.

As detailed above, in some embodiments, two independent occurrences of R⁺ (or any other variable similarly defined in the specification and claims herein), are taken together with their intervening atom(s) to form a monocyclic or bicyclic ring selected from 3-13-membered cycloaliphatic, 3-12-membered heterocyclyl having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 6-10-membered aryl, or 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

Exemplary rings that are formed when two independent occurrences of R⁺ (or any other variable similarly defined in the specification and claims herein), are taken together with their intervening atom(s) include, but are not limited to the following: a) two independent occurrences of R⁺ (or any other variable similarly defined in the specification or claims herein) that are bound to the same atom and are taken together with that atom to form a ring, for example, N(R⁺)₂, where both occurrences of R⁺ are taken together with the nitrogen atom to form a piperidin-1-yl, piperazin-1-yl, or morpholin-4-yl group; and b) two independent occurrences of R⁺ (or any other variable similarly defined in the specification or claims herein) that are bound to different atoms and are taken together with both of those atoms to form a ring, for example where a phenyl group is substituted with two occurrences of OR⁺

these two occurrences of R⁺ are taken together with the oxygen atoms to which they are bound to form a fused 6-membered oxygen containing ring:

It will be appreciated that a variety of other rings (e.g., spiro and bridged rings) can be formed when two independent occurrences of R+ (or any other variable similarly defined in the specification and claims herein) are taken together with their intervening atom(s) and that the examples detailed above are not intended to be limiting.

Unless otherwise stated, structures depicted herein are also meant to include all isomeric (e.g., enantiomeric, diastereomeric, and geometric (or conformational)) forms of the structure; for example, the R and S configurations for each asymmetric center, (Z) and (E) double bond isomers, and (Z) and (E) conformational isomers. Therefore, single stereochemical isomers as well as enantiomeric, diastereomeric, and geometric (or conformational) mixtures of the present compounds are within the scope of the invention. Unless otherwise stated, all tautomeric forms of the compounds of the invention are within the scope of the invention. Additionally, unless otherwise stated, structures depicted herein are also meant to include compounds that differ only in the presence of one or more isotopically enriched atoms. For example, compounds having the present structures except for the replacement of hydrogen by deuterium or tritium, or the replacement of a carbon by a 13C- or 14C-enriched carbon are within the scope of this invention. Such compounds are useful, for example, as analytical tools or probes in biological assays.

The terms “stereoisomer”, “enantiomer”, “diastereomer”, “epimer”, and “chiral center”, are used herein in accordance with the meaning each is given in ordinary usage by those of ordinary skill in the art. Thus, stereoisomers are compounds that have the same atomic connectivity, but differ in the spatial arrangement of the atoms. Enantiomers are stereoisomers that have a mirror image relationship, that is, the stereochemical configuration at all corresponding chiral centers is opposite. Diastereomers are stereoisomers having more than one chiral center, which differ from one another in that the stereochemical configuration of at least one, but not all, of the corresponding chiral centers is opposite. Epimers are diastereomers that differ in stereochemical configuration at only one chiral center.

It is to be understood that, when a disclosed compound has at least one chiral center, the present invention encompasses one enantiomer of the compound, substantially free from the corresponding optical isomer, a racemic mixture of both optical isomers of the compound, and mixtures enriched in one enantiomer relative to its corresponding optical isomer. When a mixture is enriched in one enantiomer relative to its optical isomer, the mixture contains, for example, an enantiomeric excess of at least 50%, 75%, 90%, 95%, 99%, or 99.5%.

The enantiomers of the present invention may be resolved by methods known to those skilled in the art, for example by formation of diastereoisomeric salts which may be separated, for example, by crystallization; formation of diastereoisomeric derivatives or complexes which may be separated, for example, by crystallization, gas-liquid or liquid chromatography; selective reaction of one enantiomer with an enantiomer-specific reagent, for example enzymatic esterification; or gas-liquid or liquid chromatography in a chiral environment, for example on a chiral support for example silica with a bound chiral ligand or in the presence of a chiral solvent. Where the desired enantiomer is converted into another chemical entity by one of the separation procedures described above, a further step is required to liberate the desired enantiomeric form. Alternatively, specific enantiomers may be synthesized by asymmetric synthesis using optically active reagents, substrates, catalysts or solvents, or by converting one enantiomer into the other by asymmetric transformation.

When a disclosed compound has at least two chiral centers, the present invention encompasses a diastereomer substantially free of other diastereomers, an enantiomeric pair of diastereomers substantially free of other stereoisomers, mixtures of diastereomers, mixtures of enantiomeric pairs of diastereomers, mixtures of diastereomers in which one diastereomer is enriched relative to the other diastereomer(s), and mixtures of enantiomeric pairs of diastereomers in which one enantiomeric pair of diastereomers is enriched relative to the other stereoisomers. When a mixture is enriched in one diastereomer or enantiomeric pair of diastereomers pairs relative to the other stereoisomers, the mixture is enriched with the depicted or referenced diastereomer or enantiomeric pair of diastereomers relative to other stereoisomers for the compound, for example, by a molar excess of at least 50%, 75%, 90%, 95%, 99%, or 99.5%.

As used herein, the term “diastereomeric ratio” refers to the ratio between diastereomers which differ in the stereochemical configuration at one chiral center, relative to a second chiral center in the same molecule. By way of example, a chemical structure with two chiral centers provides four possible stereoisomers: R*R, R*S, S*R, and S*S, wherein the asterisk denotes the corresponding chiral center in each stereoisomer. The diastereomeric ratio for such a mixture of stereoisomers is the ratio of one diastereomer and its enantiomer to the other diastereomer and its enantiomer=(R*R+S*S):(R*S+S*R).

One of ordinary skill in the art will recognize that additional stereoisomers are possible when the molecule has more than two chiral centers. For purposes of the present invention, the term “diastereomeric ratio” has identical meaning in reference to compounds with multiple chiral centers as it does in reference to compounds having two chiral centers. Thus, the term “diastereomeric ratio” refers to the ratio of all compounds having R*R or S*S configuration at the specified chiral centers to all compounds having R*S or S*R configuration at the specified chiral centers. For convenience, this ratio is referred to herein as the diastereomeric ratio at the asterisked carbon, relative to the second specified chiral center.

The diastereomeric ratio can be measured by any analytical method suitable for distinguishing between diastereomeric compounds having different relative stereochemical configurations at the specified chiral centers. Such methods include, without limitation, nuclear magnetic resonance (NMR), gas chromatography (GC), and high performance liquid chromatography (HPLC) methods.

The diastereoisomeric pairs may be separated by methods known to those skilled in the art, for example chromatography or crystallization and the individual enantiomers within each pair may be separated as described above. Specific procedures for chromatographically separating diastereomeric pairs of precursors used in the preparation of compounds disclosed herein are provided the examples herein.

3. Description of Exemplary Compounds

In some embodiments, the compound of formula (I) is represented by formulas (I-a) or (I-b):

wherein R^(1a), R^(1b), R^(a), and R¹ have the values described herein. In certain embodiments, the compound of formula (I) is represented by formula (I-a), wherein R^(1a), R^(1b), R^(a), and R¹ have the values described herein. In certain embodiments, the compound of formula (I) is represented by formula (I-b), wherein R^(1a), R^(1b), R^(a), and R¹ have the values described herein.

In some embodiments, the compound of formula (I) is represented by formulas (II-a)-(II-d):

wherein R^(1a), R^(1c), R^(a), R^(b), R^(2a), R^(2b), and R¹ have the values described herein. In some embodiments, the compound of formula (I) is represented by formulas (II-a-i)-(II-d-ii):

wherein R^(1a), R^(1c), R^(a), R^(b), and R¹ have the values described herein. In certain embodiments, the compound of formula (I) is represented by formula (II-a-i), wherein R^(1a), R^(1c), R^(a), and R¹ have the values described herein. In certain embodiments, the compound of formula (I) is represented by formula (II-a-ii), wherein R^(1a), R^(1c), R^(a), and R¹ have the values described herein. In certain embodiments, the compound of formula (I) is represented by formula (II-b-i), wherein R^(1a), R^(a), and R¹ have the values described herein. In certain embodiments, the compound of formula (I) is represented by formula (II-b-ii), wherein R^(1a), R^(a), and R¹ have the values described herein. In certain embodiments, the compound of formula (I) is represented by formula (II-c-i), wherein R^(a), R^(b), and R¹ have the values described herein. In certain embodiments, the compound of formula (I) is represented by formula (II-c-ii), wherein R^(a), R^(b), and R¹ have the values described herein.

In some embodiments, the compound of formula (I) is represented by formulas (III-a-i)-(III-d-ii):

wherein R^(1a), R^(a), R^(b), G, and G¹ have the values described herein. In certain embodiments, the compound of formula (I) is represented by formula (III-a-i), wherein R^(a) and R^(1a) have the values described herein. In certain embodiments, the compound of formula (I) is represented by formula (III-a-ii), wherein R^(a) and R^(1a) have the values described herein. In certain embodiments, the compound of formula (I) is represented by formula (III-b-i), wherein R^(a) and R^(1a) have the values described herein. In certain embodiments, the compound of formula (I) is represented by formula (III-b-ii), wherein R^(a) and R^(1a) have the values described herein. In certain embodiments, the compound of formula (I) is represented by formula (III-c-i), wherein G has the values described herein. In certain embodiments, the compound of formula (I) is represented by formula (III-c-ii), wherein G has the values described herein.

In some embodiments, the compound of formula (II-a-i) is represented by formulas (IV-a-i-a) and (IV-a-i-b)

wherein R^(1a′), R^(a′), R¹, G, and G¹ have the values described herein. In certain embodiments, the compound of formula (II-a-i) is represented by formula (IV-a-i-a), wherein R^(1a′), R¹, and G have the values described herein. In certain embodiments, the compound of formula (II-a-i) is represented by formula (IV-a-i-b), wherein R^(a′), R¹, and G¹ have the values described herein.

In some embodiments, the compound of formula (II-a-ii) is represented by formulas (IV-a-ii-a) and (IV-a-ii-b)

wherein R^(1a′), R^(a′), R¹, G, and G¹ have the values described herein. In certain embodiments, the compound of formula (II-a-ii) is represented by formula (IV-a-ii-a), wherein R^(1a′), R¹, and G have the values described herein. In certain embodiments, the compound of formula (II-a-ii) is represented by formula (IV-a-ii-b), wherein R^(1a′), R¹, and G¹ have the values described herein.

In some embodiments, the compound of formula (II-b-i) is represented by formulas (IV-b-i-a) and (IV-b-i-b)

wherein R^(1a′), R^(a′), R¹, G, and G¹ have the values described herein. In certain embodiments, the compound of formula (II-b-i) is represented by formula (IV-b-i-a), wherein R^(1a′), R¹, and G have the values described herein. In certain embodiments, the compound of formula (II-b-i) is represented by formula (IV-b-i-b), wherein R^(a′), R¹, and G¹ have the values described herein.

In some embodiments, the compound of formula (II-b-ii) is represented by formulas (IV-b-ii-a) and (IV-b-ii-b)

wherein R^(1a′), R^(a′), R¹, G, and G¹ have the values described herein. In certain embodiments, the compound of formula (II-b-ii) is represented by formula (IV-b-ii-a), wherein R^(1a′), R¹, and G have the values described herein. In certain embodiments, the compound of formula (II-b-ii) is represented by formula (IV-b-ii-b), wherein R^(a′), R¹, and G¹ have the values described herein.

In some embodiments, the compound of formula (II-a-i) is represented by formulas (V-a-i-a) and (V-a-i-b)

wherein R^(1a′), R^(a′), G, and G¹ have the values described herein. In certain embodiments, the compound of formula (II-a-i) is represented by formula (V-a-i-a), wherein R^(1a′) and G have the values described herein. In certain embodiments, the compound of formula (II-a-i) is represented by formula (V-a-i-b), wherein R^(a′) and G¹ have the values described herein.

In some embodiments, the compound of formula (II-a-ii) is represented by formulas (V-a-ii-a) and (V-a-ii-b)

wherein R^(1a′), R^(a′), G, and G¹ have the values described herein. In certain embodiments, the compound of formula (II-a-ii) is represented by formula (V-a-ii-a), wherein R^(1a′) and G have the values described herein. In certain embodiments, the compound of formula (II-a-ii) is represented by formula (V-a-ii-b), wherein R^(a′) and G¹ have the values described herein.

In some embodiments, the compound of formula (II-b-i) is represented by formulas (V-b-i-a) and (V-b-i-b)

wherein R^(1a′), R^(a′), G, and G¹ have the values described herein. In certain embodiments, the compound of formula (II-b-i) is represented by formula (V-b-i-a), wherein R^(1a′) and G have the values described herein. In certain embodiments, the compound of formula (II-b-i) is represented by formula (V-b-i-b), wherein R^(a′) and G¹ have the values described herein.

In some embodiments, the compound of formula (II-b-ii) is represented by formulas (V-b-ii-a) and (V-b-ii-b)

wherein R^(1a′), R^(a′), G, and G¹ have the values described herein. In certain embodiments, the compound of formula (II-b-ii) is represented by formula (V-b-ii-a), wherein R^(1a′) and G have the values described herein. In certain embodiments, the compound of formula (II-b-ii) is represented by formula (V-b-ii-b), wherein R^(a′) and G¹ have the values described herein.

The values described below for each variable are with respect to any of formulas (I), (II), (III), (IV), (V), or their sub-formulas as described above.

Each occurrence of the variable R¹ is independently hydrogen, chloro, fluoro, cyano, hydroxy, C₁₋₄ alkyl, or C₁₋₄ fluoroalkyl. In some embodiments, each occurrence of R¹ is independently hydrogen, chloro, fluoro, cyano, hydroxy, methoxy, ethoxy, trifluoromethyl, methyl, or ethyl. In certain embodiments, each occurrence of R¹ is independently hydrogen, fluoro, or methyl. In certain embodiments, each occurrence of R¹ is hydrogen.

One of the variable R^(2a) and R^(2b) is R¹, and the other is —C(O)—NH—OH, wherein R¹ has the values described herein. In same embodiments, R^(2a) is R¹ and R^(2b) is —C(O)—NH—OH, wherein R¹ has the values described herein. In some embodiments, R^(2b) is R¹ and R^(2a) is —C(O)—NH—OH, wherein R¹ has the values described herein.

The variable X is C(R^(1c))(R^(1d)) or N—R^(b), wherein R^(1c), R^(1d), and R^(b) have the values described herein. In some embodiments, X is C(R^(1c))(R^(1d)), wherein R^(1c) and R^(1d) have the values described herein. In some embodiments, X is N—R^(b), wherein R^(b) has the values described herein.

The variable R^(1c) is hydrogen, fluoro, bromo, —CH₂—OR^(4aa), —CH₂N(R^(4aa))₂, or C₁₋₄ alkyl, wherein R^(4aa) has the values described herein. In some embodiments, R^(1c) is hydrogen, fluoro, or C₁₋₄ alkyl. In some embodiments, R^(1c) is hydrogen, fluoro or methyl. In certain embodiments, R^(1c) is hydrogen. In some embodiments, R^(1c) is —CH₂—OR^(4aa) or —CH₂N(R^(4aa))₂, wherein R^(4aa) has the values described herein. In some embodiments, R^(1c) is —CH₂—OH or —CH₂NH₂.

The variable R^(1a) is hydrogen, fluoro, C₁₋₄ alkyl, C₁₋₄ fluoroalkyl, or G¹; or when X is N—R^(b), R^(1a) can be taken together with R^(1b) to form C═O, wherein R^(b) and G¹ have the values described herein. In some embodiments, R^(1a) is hydrogen, fluoro, C₁₋₄ alkyl, C₁₋₄ fluoroalkyl, or G¹, wherein G¹ has the values described herein. In some embodiments, R^(1a) is hydrogen, fluoro, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, trifluoromethyl, or G¹, wherein G¹ has the values described herein. In certain embodiments, R^(1a) is hydrogen, fluoro, methyl, or G¹, wherein G¹ has the values described herein. In certain embodiments, R^(1a) is hydrogen, fluoro, or methyl. In certain embodiments, R^(1a) is hydrogen. In certain embodiments, R^(1a) is G¹, wherein G¹ has the values described herein. In some embodiments, when X is N—R^(b), R^(1a) can be taken together with R^(1b) to form C═O, wherein R^(b) has the values described herein.

The variable R^(1a′) is hydrogen, fluoro, or C₁₋₄ alkyl. In some embodiments, R^(1a′) is hydrogen, fluoro, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, or tert-butyl. In certain embodiments, R^(1a′) is hydrogen, methyl, ethyl, or isopropyl. In certain embodiments, R^(1a′) is hydrogen.

The variable R^(1d) is taken together with R^(1b) to form a double bond.

When X is C(R^(1c))(R^(1d)), the variable R^(1b) is taken together with R^(1d) to form a double bond; and when X is N—R^(b), R^(1b) is taken together with R^(b) to form a double bond, or is taken together with R^(a) to form a double bond, or is taken together with R^(1a) to form C═O. In some embodiments, when X is C(R^(1c))(R^(1d)), R^(1b) is taken together with R^(1d) to form a double bond, wherein R^(1c) has the values described herein. In some embodiments, when X is N—R^(b), R^(1b) is taken together with R^(b) to form a double bond. In some embodiments, when X is N—R^(b), R^(1b) is taken together with R^(a) to form a double bond, wherein R^(b) has the values described herein. In some embodiments, when X is N—R^(b), R^(1b) is taken together with R^(1a) to form C═O, wherein R^(b) has the values described herein.

The variable R^(b) is hydrogen, C₁₋₆ alkyl, benzyl, or phenyl; or R^(b) is taken together with R^(1b) to form a double bond. In some embodiments, R^(b) is hydrogen, C₁₋₆ alkyl, benzyl, or phenyl. In certain embodiments, R^(b) is hydrogen, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, benzyl, or phenyl. In certain embodiments, R^(b) is hydrogen, methyl, benzyl or phenyl. In certain embodiments R^(b) is hydrogen or methyl. In some embodiments, R^(b) is taken together with R^(1b) to form a double bond.

The variable R^(a) is hydrogen, C₁₋₄ alkyl, or G; or when X is N—R^(b), R^(1b) can be taken together with R^(a) to form a double bond. In some embodiments, R^(a) is hydrogen, C₁₋₄ alkyl, or G, wherein G has the values described herein. In some embodiments, R^(a) is hydrogen, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, or G, wherein G has the values described herein. In certain embodiments, R^(a) is hydrogen, methyl, or G, wherein G has the values described herein. In certain embodiments, R^(a) is hydrogen or methyl. In certain embodiments, R^(a) is hydrogen. In certain embodiments, R^(a) is G, wherein G has the values described herein. In some embodiments, when X is N—R^(b), R^(1b) can be taken together with R^(a) to form a double bond.

The variable R^(a′) is hydrogen, or C₁₋₄ alkyl. In some embodiments, R^(a′) is hydrogen, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, or tert-butyl. In certain embodiments, R^(a′) is hydrogen, methyl, or isopropyl. In certain embodiments, R^(a′) is hydrogen or methyl. In certain embodiments, R^(a′) is hydrogen.

The variable G is hydrogen, —R³, -L₁-R³, or -L₂-V₁—R³, wherein R³, L₁, L₂ and V₁ have the values described herein. In some embodiments, G is -L₁-R³, or -L₂-V₁—R³, wherein R³, L₁, L₂ and V₁ have the values described herein. In certain embodiments, G is -L₁-R³, wherein R³ and L₁ have the values described herein. In certain embodiments, G is -L₂-V₁—R³, wherein R³, L₂ and V₁ have the values described herein.

The variable G¹ is —NH₂, —R³, -L₁-R³, —V₂—R³, -L₁-V₂—R³, or —V₂-L₁-R³, wherein R³, L₁, and V₂ have the values described herein. In some embodiments, G¹ is —R³, -L₁-R³, or —V₂—R³, wherein R³, L₁, and V₂ have the values described herein. In some embodiments, G¹ is —R³ or -L₁-R³, wherein R³ and L₁ have the values described herein. In certain embodiments, G¹ is —R³, wherein R³ has the values described herein. In certain embodiments, G¹ is -L₁-R³, wherein L₁ and R³ has the values described herein. In certain embodiments, G¹ is -V₂-R³, wherein R³ and V₂ have the values described herein.

The variable L₁ is an unsubstituted or substituted C₁₋₄ alkylene chain. In some embodiments, L₁ is —CH₂—, —CH₂CH₂—, —CH₂CH₂CH₂—, —CH₂CH₂CH₂CH₂—, —CR^(A)═CR^(A), or In some embodiments, L₁ is —CH₂—, —CH₂CH₂—, or —CH₂CH₂CH₂—. In certain embodiments, L₁ is —CH₂—. In certain embodiments, L₁ is —CH₂CH₂—. In certain embodiments, L₁ is —C(R¹¹)(R^(11a))—, —C(R¹¹)(R^(11a))—C(R¹¹)(R^(11a))—, or —C(R¹¹)(R^(11a))—C(R¹¹)(R^(11a))—C(R¹¹)(R^(11a))—, wherein R¹¹ and R^(11a) have has the values described herein.

The variable L₂ is an unsubstituted or substituted C₂₋₃ alkylene chain. In some embodiments, L₂ is —CH₂CH₂— or —CH₂CH₂CH₂—. In certain embodiments, L₂ is —CH₂CH₂—. In certain embodiments, L₂ is —CH₂CH₂CH₂—. In certain embodiments, L₂ is —C(R¹¹)(R^(11a))—C(R¹¹)(R^(11a))— or —C(R¹¹)(R^(11a))—C(R¹¹)(R^(11a))—C(R¹¹)(R^(11a))—, wherein R¹¹ and R^(11a) have the values described herein.

Each occurrence of the variable R¹¹ is independently hydrogen, unsubstituted or substituted C₁₋₄ aliphatic, unsubstituted or substituted 3-10-membered cycloaliphatic, unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur. In some embodiments, each occurrence of R¹¹ is hydrogen or C₁₋₄ alkyl. In certain embodiments, each occurrence of R¹¹ is independently hydrogen, methyl, ethyl, isopropyl, or butyl. In certain embodiments, each occurrence of R¹¹ is independently hydrogen or methyl.

Each occurrence of the variable R^(11a) is independently hydrogen or C₁₋₄ alkyl. In certain embodiments, each occurrence of R^(11a) is independently hydrogen or methyl. In certain embodiments, R^(11a) is hydrogen.

In some embodiments, one occurrence of R¹¹ and once occurrence of R^(11a) on the same carbon atom can be taken together to form a 3-6 membered cycloaliphatic ring. In certain embodiments, one occurrence of R¹¹ and once occurrence of R^(11a) on the same carbon atom can be taken together to form cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl.

Each occurrence of the variable R^(A) is independently hydrogen, fluoro, or unsubstituted or substituted C₁₋₄ aliphatic. In some embodiments, each occurrence of R^(A) is independently hydrogen, fluoro or methyl. In certain embodiments, each occurrence of R^(A) is hydrogen.

The variable V₁ is —O—, —N(R^(4a))—, —S—, —N(R^(4a))—C(O)—, —C(O)—N(R^(4a))—, —SO₂—N(R^(4a))—, —N(R^(4a))—SO₂—, —SO₂—, or —N(R^(4a))—C(O)—N(R^(4a))—, wherein R^(4a) has the values described herein. In some embodiments, V₁ is —O—, —N(R^(4a))—, —N(R^(4a))—C(O)—, —C(O)—N(R^(4a))—, —SO₂—N(R^(4a))—, —N(R^(4a))—SO₂—, or —N(R^(4a))—C(O)—N(R^(4a))—, wherein R^(4a) has the values described herein. In some embodiments, V₁ is —O—, —NH—, —NH—C(O)—, —C(O)—NH—, —SO₂—NH—, —NH—SO₂—, or —NH—C(O)—NH—. In certain embodiments, V₁ is —O— or —N(R^(4a))—, wherein R^(4a) has the values described herein. In certain embodiments, V₁ is —O— or —NH—.

The variable V₂ is —O—, —N(R^(4a))—, —C(O)—N(R^(4a))—, —N(R^(4a))—C(O)—N(R^(4a))—, or —N(R^(4a))—C(O)—O—, wherein R^(4a) has the values described herein. In some embodiments, V₂ is —N(R^(4a))— or —C(O)—N(R^(4a))—, wherein R^(4a) has the values described herein. In certain embodiments, V₂ is —NH—, —C(O)—NH—, —NH—C(O)—NH—, or —NH—C(O)—O—. In certain embodiments, V₂ is —NH—, or —C(O)—NH—. In certain embodiments, V₂ is —NH—.

Each occurrence of the variable R^(4aa) is independently hydrogen or C₁₋₄ alkyl. In some embodiments, each occurrence of R^(4aa) is independently hydrogen, methyl, ethyl, isopropyl, propyl, butyl, isobutyl, or tert-butyl. In certain embodiments, each occurrence of R^(4aa) is independently hydrogen or methyl. In certain embodiments, R^(4aa) is hydrogen.

Each occurrence of the variable R^(4a) is independently hydrogen, unsubstituted or substituted C₁₋₄ aliphatic, unsubstituted or substituted 3-10-membered cycloaliphatic, unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur. In some embodiments, each occurrence of R^(4a) is independently hydrogen, methyl, ethyl, isopropyl, butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, benzyl or phenyl. In some embodiments, each occurrence of R^(4a) is independently hydrogen, or methyl. In certain embodiments, R^(4a) is hydrogen.

The variable R³ is unsubstituted or substituted C₁₋₆ aliphatic, unsubstituted or substituted 3-10-membered cycloaliphatic, unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur.

In some embodiments, R³ is unsubstituted or substituted C₁₋₆ aliphatic, unsubstituted or substituted 3-10-membered cycloaliphatic, unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur; wherein:

each substitutable carbon chain atom in R³ is unsubstituted or substituted with 1-2 occurrences of R^(5dd);

each substitutable saturated ring carbon atom in R³ is unsubstituted or substituted with ═O, ═C(R⁵)₂, or —R^(5aa);

each substitutable unsaturated ring carbon atom in R³ is unsubstituted or is substituted with —R^(5a);

each substitutable ring nitrogen atom in R³ is unsubstituted or substituted with —R^(9b);

wherein R^(5dd), R⁵, R^(5a), R^(5aa), and R^(9b) have the values described herein.

In some embodiments, R³ is unsubstituted or substituted C₁₋₆ aliphatic, unsubstituted or substituted 3-10-membered cycloaliphatic, unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur; wherein:

-   -   each substitutable carbon chain atom in R³ is unsubstituted or         substituted with 1-2 occurrences of —R^(5dd);     -   each substitutable saturated ring carbon atom in R³ is         unsubstituted or substituted with —R^(5a);     -   each substitutable unsaturated ring carbon atom in R³ is         unsubstituted or is substituted with —R^(5a);     -   the total number of R^(5a) and R^(5aa) substituents is p; and     -   each substitutable ring nitrogen atom in R³ is unsubstituted or         substituted with —R^(9b);     -   wherein R^(5dd), R^(5a), R^(9b) and p have the values described         herein.

Each occurrence of the variable R^(5dd) is independently fluoro, hydroxy, —O—(C₁₋₆ alkyl), cyano, —N(R⁴)₂, —C(O)(C₁₋₆ alkyl), —CO₂H, —C(O)NH₂, —C(O)NH(C₁₋₆ alkyl), —C(O)N(C₁₋₆ alkyl)₂, —NHC(O)C₁₋₆ alkyl, —NHC(O)OC₁₋₆ alkyl, —NHC(O)NHC₁₋₆alkyl, or —NHS(O)₂C₁₋₆ alkyl, wherein R⁴ has the values described herein. In some embodiments, each occurrence of R^(5dd) is independently fluoro, hydroxy, methoxy, ethoxy, —NH(C₁₋₆ alkyl), —N(C₁₋₆ alkyl)₂, or —C(O)NHCH₃.

Each occurrence of the variable R^(9b) is independently —C(O)R⁶, —C(O)N(R⁴)₂, —CO₂R⁶, —SO₂R⁶, —SO₂N(R⁴)₂, unsubstituted C₃₋₁₀ cycloaliphatic, C₃₋₁₀ cycloaliphatic substituted with 1-2 independent occurrences of R⁷ or R⁸, unsubstituted C₁₋₆ aliphatic, or C₁₋₆ aliphatic substituted with 1-2 independent occurrences of R⁷ or R⁸, wherein R⁷ and R⁸ have the values described herein. In some embodiments, each occurrence of R^(9b) is independently unsubstituted —C(O)—C₁₋₆ aliphatic, unsubstituted —C(O)—C₃₋₁₀ cycloaliphatic, or unsubstituted C₁₋₆ aliphatic. In some embodiments, each occurrence of R^(9b) is unsubstituted C₁₋₆ aliphatic. In certain embodiments, each occurrence of R^(9b) is independently methyl, ethyl, isopropyl, isobutyl, n-propyl, n-butyl, tert-butyl, —C(O)-methyl, —C(O)-ethyl, —C(O)-cyclopropyl, —C(O)-tert-butyl, —C(O)-isopropyl, or —C(O)-cyclobutyl. In certain embodiments, each occurrence of R^(9b) is independently methyl, ethyl, isopropyl, isobutyl, n-propyl, n-butyl, or tert-butyl.

Each occurrence of the variable R⁴ is independently hydrogen, unsubstituted or substituted C₁₋₆ aliphatic, unsubstituted or substituted 3-10-membered cycloaliphatic, unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur; or two R⁴ on the same nitrogen atom, taken together with the nitrogen atom, form an unsubstituted or substituted 5- to 6-membered heteroaryl or an unsubstituted or substituted 4- to 8-membered heterocyclyl having, in addition to the nitrogen atom, 0-2 ring heteroatoms selected from nitrogen, oxygen, and sulfur.

Each occurrence of the variable R⁵ is independently hydrogen, unsubstituted or substituted C₁₋₆ aliphatic, unsubstituted or substituted 3-10-membered cycloaliphatic, unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur.

Each occurrence of the variable R⁶ is independently unsubstituted or substituted C₁₋₆ aliphatic, unsubstituted or substituted 3-10-membered cycloaliphatic, unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur.

Each occurrence of the variable R⁷ is independently unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur.

Each occurrence of the variable R⁸ is independently chloro, fluoro, —OR⁵, —CN, —N(R⁴)₂, —C(O)(C₁₋₆ alkyl), —CO₂H, —CO₂(C₁₋₆ alkyl), —C(O)NH₂, —C(O)NH(C₁₋₆ alkyl), or —C(O)N(C₁₋₆ alkyl)₂, wherein R⁴ and R⁵ have the values described herein.

Each occurrence of the variable R^(5a) is independently halogen, —NO₂, —CN, —C(R⁵)═C(R⁵)₂, —C≡C—R⁵, —OR⁵, —SR⁶, —S(O)R⁶, —SO₂R⁶, —SO₂N(R⁴)₂, —N(R⁴)₂, —NR⁴C(O)R⁶, —NR⁴C(O)N(R⁴)₂, —NR⁴CO₂R⁶, —OC(O)N(R⁴)₂, —C(O)R⁶, —C(O)N(R⁴)₂, —N(R⁴)SO₂R⁶, —N(R⁴)SO₂N(R⁴)₂, unsubstituted or substituted C₁₋₆ aliphatic, unsubstituted or substituted 3-10-membered cycloaliphatic, unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur; or two adjacent R^(5a), taken together with the intervening ring atoms, form an unsubstituted or substituted fused 5-10 membered aromatic ring or an unsubstituted or substituted 4-10 membered non-aromatic ring having 0-3 heteroatoms independently selected from nitrogen, oxygen, and sulfur, wherein R⁵, R⁶, and R⁴ have the values described herein.

In some embodiments, each occurrence of R^(5a) is independently halogen, cyano, nitro, hydroxy, unsubstituted C₁₋₆ aliphatic, C₁₋₆ aliphatic substituted with 1-2 independent occurrences of R⁷ or R⁸, unsubstituted —O—C₁₋₆ alkyl, —O—C₁₋₆ alkyl substituted with 1-2 independent occurrences of R⁷ or R⁸, C₁₋₆ fluoroalkyl, —O—C₁₋₆ fluoroalkyl, —NHC(O)R⁶, —C(O)NH(R⁴), —NHC(O)O—C₁₋₆ alkyl, —NHC(O)NHC₁₋₆ alkyl, —NHS(O)₂C₁₋₆ alkyl, —NHC₁₋₆ alkyl, —N(C₁₋₆alkyl)₂, 3-10-membered cycloaliphatic substituted with 0-2 occurrences of —R^(7a), 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur substituted with 0-2 occurrences of —R^(7a), 6-10-membered aryl substituted with 0-2 occurrences of —R^(7a), or 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur substituted with 0-2 occurrences of —R^(7a), wherein R⁴, R⁵, R^(7a), R⁷, and R⁸ have the values described herein.

In certain embodiments, each occurrence of R^(5a) is independently chloro, fluoro, hydroxy, methoxy, ethoxy, cyano, trifluoromethyl, methyl, ethyl, isopropyl, —NHC(O)-tert-butyl, —NHC(O)-cyclopropyl, —NHC(O)R¹⁰, —C(O)NHR¹⁰, —CH₂—N(R⁴)₂, or —NHSO₂CH₃, wherein R¹⁰ has the values described herein.

Each occurrence of the variable R¹⁰ is unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur. In some embodiments, each occurrence of R¹⁰ is unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, wherein if substituted R¹⁰ is substituted with 0-2 occurrences of —R^(7aa), wherein R^(7aa) has the values described herein. In some embodiments, each occurrence of R¹⁰ is pyrrolidinyl, piperidinyl, pyrrolinyl, piperazinyl, or morpholinyl, wherein each of the foregoing groups is unsubstituted or substituted with 0-1 occurrence of R^(7aa), wherein R^(7aa) has the values described herein.

Each occurrence of the variable R^(5aa) is independently chloro, fluoro, hydroxy, unsubstituted or substituted C₁₋₆ aliphatic, —O(C₁₋₆ alkyl), —C₁₋₆ fluoroalkyl, —O—C₁₋₆ fluoroalkyl, cyano, —N(R⁴)₂, —C(O)(C₁₋₆ alkyl), —CO₂H, —C(O)NH₂, —C(O)NH(C₁₋₆ alkyl), —C(O)N(C₁₋₆ alkyl)₂, —NHC(O)C₁₋₆ alkyl, —NHC(O)OC₁₋₆ alkyl, —NHC(O)NHC₁₋₆ alkyl, —NHC(O)N(C₁₋₆ alkyl)₂, or —NHS(O)₂C₁₋₆ alkyl. In some embodiments, each occurrence of R^(5aa) is independently chloro, fluoro, hydroxy, methyl, ethyl, methoxy, ethoxy, trifluoromethyl, trifluoromethoxy, —C(O)NH₂, —N(C₁₋₆ alkyl)₂, —NHC₁₋₆ alkyl, or —CO₂H. In certain embodiments, each occurrence of R^(5aa) is independently fluoro, methyl, ethyl, methoxy, ethoxy, —C(O)NH₂, —N(C₁₋₆ alkyl)₂, —NHC₁₋₆ alkyl, or —CO₂H.

Each occurrence of R^(7a) is independently chloro, fluoro, C₁₋₆ aliphatic, C₁₋₆ fluoroalkyl, —O—C₁₋₆ alkyl, —O—C₁₋₆ fluoroalkyl, cyano, hydroxy, —CO₂H, —NHC(O)C₁₋₆ alkyl, —NH₂, —NHC₁₋₆ alkyl, —N(C₁₋₆ alkyl)₂, —C(O)NHC₁₋₆ alkyl, —C(O)N(C₁₋₆ alkyl)₂, —NHC(O)NHC₁₋₆ alkyl, —NHC(O)N(C₁₋₆ alkyl)₂, or —NHS(O)₂C₁₋₆ alkyl. In certain embodiments, each occurrence of the variable R^(7a) is independently chloro, fluoro, hydroxy, methoxy, ethoxy, cyano, trifluoromethyl, trifluoromethoxy, methyl, ethyl, isopropyl, —CO₂H, or —NH₂.

Each occurrence of the variable R^(7aa) is independently chloro, fluoro, hydroxy, unsubstituted or substituted C₁₋₆ aliphatic, —O(C₁₋₆ alkyl), —C₁₋₆ fluoroalkyl, —O—C₁₋₆ fluoroalkyl, cyano, —N(R⁴)₂, —C(O)(C₁₋₆ alkyl), —CO₂H, —C(O)NH₂, —C(O)NH(C₁₋₆ alkyl), —C(O)N(C₁₋₆ alkyl)₂, —NHC(O)C₁₋₆ alkyl, —NHC(O)OC₁₋₆ alkyl, —NHC(O)NHC₁₋₆alkyl, —NHC(O)N(C₁₋₆alkyl)₂, or —NHS(O)₂C₁₋₆ alkyl. In some embodiments, each occurrence of R^(7aa) is independently fluoro, hydroxy, methyl, ethyl, methoxy, trifluoromethyl, —C(O)NH₂, or —CO₂H.

The variable p is 1-4. In some embodiments, p is 1-3. In certain embodiments, p is 1-2. In certain embodiments, p is 1.

In some embodiments, R³ is unsubstituted or substituted C₁₋₆ aliphatic. In some embodiments, each substitutable carbon chain atom in R³ is unsubstituted or substituted with 1-2 occurrences of —R^(5dd), wherein R^(5dd) has the values described herein. In certain embodiments, R³ is methyl, ethyl, n-propyl, isopropyl, tert-butyl, n-butyl, iso-butyl, pentyl, hexyl, butenyl, propenyl, pentenyl, or hexenyl, wherein each of the aforementioned groups is unsubstituted or substituted. In certain embodiments, R³ is methyl, ethyl, n-propyl, isopropyl, tert-butyl, n-butyl, iso-butyl, pentyl, hexyl, butenyl, propenyl, pentenyl, or hexenyl, wherein each substitutable carbon chain atom in R³ is unsubstituted or substituted with 1-2 occurrences of —R^(5dd), wherein R^(5dd) has the values described herein.

In some embodiments, R³ is unsubstituted or substituted 3-10-membered cycloaliphatic, unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur.

In certain embodiments, R³ is unsubstituted or substituted 3-10-membered cycloaliphatic, unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur, wherein:

each substitutable saturated ring carbon atom in R³ is unsubstituted or substituted with ═O, ═C(R)₂, or —R^(5aa);

each substitutable unsaturated ring carbon atom in R³ is unsubstituted or is substituted with —R^(5a); and

each substitutable ring nitrogen atom in R³ is unsubstituted or substituted with —R^(9b);

wherein R⁵, R^(5a), R^(5aa), and R^(9b) have the values described herein.

In certain embodiments, R³ is unsubstituted or substituted 3-10-membered cycloaliphatic, unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur, wherein:

-   -   each substitutable saturated ring carbon atom in R³ is         unsubstituted or substituted with —R^(5aa);     -   each substitutable unsaturated ring carbon atom in R³ is         unsubstituted or is substituted with —R^(5a);     -   the total number of R^(5a) and R^(5aa) substituents is p; and     -   each substitutable ring nitrogen atom in R³ is unsubstituted or         substituted with —R^(9b);     -   wherein R^(5a), R^(5aa), R^(9b) and p have the values described         herein.

In certain embodiments, R³ is furanyl, thienyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, triazolyl, thiadiazolyl, phenyl, naphthyl, pyranyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, indolizinyl, imidazopyridyl, indolyl, isoindolyl, indazolyl, benzimidazolyl, benzthiazolyl, benzothienyl, benzofuranyl, benzoxazolyl, benzodioxolyl, benzthiadiazolyl, 2,3-dihydrobenzofuranyl, 4H-furo[3,2-b]pyrrolyl, pyrazolopyrimidinyl, purinyl, quinolyl, isoquinolyl, tetrahydroquinolinyl, tetrahydronaphthyridinyl, tetrahydroisoquinolinyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, naphthyridinyl, pteridinyl, tetrahydrofuranyl, tetrahydropyranyl, tetrahydrothienyl, indanyl, tetrahydroindazolyl, pyrrolidinyl, pyrrolidonyl, piperidinyl, pyrrolinyl, decahydroquinolinyl, oxazolidinyl, piperazinyl, dioxanyl, diazepinyl, oxazepinyl, thiazepinyl, morpholinyl, thiomorpholinyl, quinuclidinyl, phenanthridinyl, tetrahydronaphthyl, indolinyl, benzodioxanyl, chromanyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl, bicycloheptanyl, azabicyclooctanyl, oxabicyclooctanyl, bicyclononyl, bicyclooctanyl, or adamantyl; wherein:

each substitutable saturated ring carbon atom in R³ is unsubstituted or substituted with ═O, ═C(R⁵)₂, or —R^(5aa);

each substitutable unsaturated ring carbon atom in R³ is unsubstituted or is substituted with —R^(5a); and

each substitutable ring nitrogen atom in R³ is unsubstituted or substituted with —R^(9b);

wherein R⁵, R^(5a), R^(5aa), and R^(9b) have the values described herein.

In certain embodiments, R³ is furanyl, thienyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, triazolyl, thiadiazolyl, phenyl, naphthyl, pyranyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, indolizinyl, imidazopyridyl, indolyl, isoindolyl, indazolyl, benzimidazolyl, benzthiazolyl, benzothienyl, benzofuranyl, benzoxazolyl, benzodioxolyl, benzthiadiazolyl, 2,3-dihydrobenzofuranyl, 4H-furo[3,2-b]pyrrolyl, pyrazolopyrimidinyl, purinyl, quinolyl, isoquinolyl, tetrahydroquinolinyl, tetrahydronaphthyridinyl, tetrahydroisoquinolinyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, naphthyridinyl, pteridinyl, tetrahydrofuranyl, tetrahydropyranyl, tetrahydrothienyl, indanyl, tetrahydroindazolyl, pyrrolidinyl, pyrrolidonyl, piperidinyl, pyrrolinyl, decahydroquinolinyl, oxazolidinyl, piperazinyl, dioxanyl, diazepinyl, oxazepinyl, thiazepinyl, morpholinyl, thiomorpholinyl, quinuclidinyl, phenanthridinyl, tetrahydronaphthyl, indolinyl, benzodioxanyl, chromanyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl, bicycloheptanyl, azabicyclooctanyl, oxabicyclooctanyl, bicyclononyl, bicyclooctanyl, or adamantyl; wherein:

-   -   each substitutable saturated ring carbon atom in R³ is         unsubstituted or substituted with —R^(5aa);     -   each substitutable unsaturated ring carbon atom in R³ is         unsubstituted or is substituted with —R^(5a);     -   the total number of R^(5a) and R^(5aa) substituents is p; and     -   each substitutable ring nitrogen atom in R³ is unsubstituted or         substituted with —R^(9b);     -   wherein R^(5a), R^(5aa), R^(9b), and p have the values described         herein.

In certain embodiments, R³ is furanyl, thienyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, triazolyl, thiadiazolyl, phenyl, pyranyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, or triazinyl; wherein:

each substitutable unsaturated ring carbon atom in R³ is unsubstituted or substituted with —R^(5a);

each occurrence of R^(5a) is independently chloro, fluoro, hydroxy, methoxy, ethoxy, cyano, trifluoromethyl, methyl, ethyl, isopropyl, —NHC(O)-tert-butyl, —NHC(O)-cyclopropyl, —NHC(O)R¹⁰, —C(O)NHR¹⁰, —CH₂—N(R⁴)₂, or —NHSO₂CH₃;

the total number of R^(5a) substituents is p; each substitutable ring nitrogen atom in R³ is unsubstituted or substituted with —R^(9b); and

each occurrence of R^(9b) is independently methyl, ethyl, isopropyl, isobutyl, n-propyl, n-butyl, or tert-butyl;

wherein p and R¹⁰ have the values described herein.

In certain embodiments, R³ is indolizinyl, imidazopyridyl, indolyl, indazolyl, benzimidazolyl, benzthiazolyl, benzothienyl, benzofuranyl, benzoxazolyl, benzthiadiazolyl, pyrazolopyrimidinyl, purinyl, quinolyl, isoquinolyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, naphthyridinyl, naphthyl, or pteridinyl; wherein:

each substitutable unsaturated ring carbon atom in R³ is unsubstituted or substituted with —R^(5a);

each occurrence of R^(5a) is independently chloro, fluoro, hydroxy, methoxy, ethoxy, cyano, trifluoromethyl, methyl, ethyl, isopropyl, —NHC(O)-tert-butyl, —NHC(O)-cyclopropyl, —NHC(O)R¹⁰, —C(O)NHR¹⁰, —CH₂—N(R⁴)₂, or —NHSO₂CH₃;

the total number of R^(5a) substituents is p;

each substitutable ring nitrogen atom in R³ is unsubstituted or substituted with —R^(9b); and

each R^(9b) is independently methyl, ethyl, isopropyl, isobutyl, n-propyl, n-butyl, or tert-butyl;

wherein p and R¹⁰ have the values described herein.

In certain embodiments, R³ is tetrahydrofuranyl, tetrahydropyranyl, tetrahydrothienyl, pyrrolidinyl, pyrrolidonyl, piperidinyl, pyrrolinyl, oxazolidinyl, piperazinyl, dioxanyl, diazepinyl, oxazepinyl, thiazepinyl, morpholinyl, thiomorpholinyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, or cyclooctenyl; wherein:

each substitutable saturated ring carbon atom in R³ is unsubstituted or substituted with —R^(5aa);

each substitutable unsaturated ring carbon atom in R³ is unsubstituted or is substituted with —R^(5a);

the total number of R^(5a) and R^(5aa) substituents is p;

each substitutable ring nitrogen atom in R³ is unsubstituted or substituted with —R^(9b);

each occurrence of R^(5a) is independently chloro, fluoro, hydroxy, methoxy, ethoxy, cyano, trifluoromethyl, methyl, ethyl, isopropyl, —NHC(O)-tert-butyl, —NHC(O)-cyclopropyl, —NHC(O)R¹⁰, —C(O)NHR¹⁰, —CH₂—N(R⁴)₂, or —NHSO₂CH₃;

each occurrence of R^(5aa) is independently chloro, fluoro, hydroxy, methyl, ethyl, methoxy, ethoxy, trifluoromethyl, trifluoromethoxy, —C(O)NH₂, —N(C₁₋₆ alkyl)₂, —NHC₁₋₆ alkyl, or —CO₂H; and

each R^(9b) is independently methyl, ethyl, isopropyl, isobutyl, n-propyl, n-butyl, tert-butyl, —C(O)-methyl, —C(O)-ethyl, —C(O)-cyclopropyl, —C(O)-tert-butyl, —C(O)-isopropyl, or —C(O)-cyclobutyl;

wherein R¹⁰ and p have the values described herein.

In certain embodiments, R³ is pyrrolidinyl, piperidinyl, or piperazinyl; wherein:

-   -   each substitutable saturated ring carbon atom in R³ is         unsubstituted or substituted with —R^(5aa);     -   the total number of R^(5aa) substituents is p; and     -   each substitutable ring nitrogen atom in R³ is unsubstituted or         substituted with —R^(9b);     -   wherein R^(5aa), p, and R^(9b) have the values described herein.

In certain embodiments, R³ is pyrrolidinyl, piperidinyl, or piperazinyl; wherein:

-   -   each substitutable saturated ring carbon atom in R³ is         unsubstituted or substituted with —R⁵″;     -   the total number of R^(5aa) substituents is p;     -   each substitutable ring nitrogen atom in R³ is unsubstituted or         substituted with —R^(9b);     -   each occurrence of R^(5aa) is independently chloro, fluoro,         hydroxy, methyl, ethyl, methoxy, ethoxy, trifluoromethyl,         trifluoromethoxy, —C(O)NH₂, —N(C₁₋₆ alkyl)₂, —NHC₁₋₆ alkyl, or         —CO₂H;

each occurrence of R^(9b) is independently methyl, ethyl, isopropyl, isobutyl, n-propyl, n-butyl, tert-butyl, —C(O)-methyl, —C(O)-ethyl, —C(O)-cyclopropyl, —C(O)-tert-butyl, —C(O)-isopropyl, or —C(O)-cyclobutyl; and

-   -   p is 1-2.

In certain embodiments, R³ is tetrahydroindazolyl, bicycloheptanyl, azabicyclooctanyl, oxabicyclooctanyl, bicyclononyl, bicyclooctanyl, adamantyl, isoindolyl, benzodioxolyl, 2,3-dihydrobenzofuranyl, 4H-furo[3,2-b]pyrrolyl, quinuclidinyl, tetrahydroquinolinyl, tetrahydronaphthyridinyl, tetrahydroisoquinolinyl, decahydroquinolinyl, tetrahydronaphthyl, indolinyl, benzodioxanyl, chromanyl, tetrahydroindazolyl, or indanyl; wherein:

-   -   each substitutable saturated ring carbon atom in R³ is         unsubstituted or substituted with —R⁵″;     -   each substitutable unsaturated ring carbon atom in R³ is         unsubstituted or is substituted with —R^(5a);     -   the total number of R^(5a) and R^(5aa) substituents is p;     -   each substitutable ring nitrogen atom in R³ is unsubstituted or         substituted with —R^(9b);     -   each occurrence of R^(5a) is independently chloro, fluoro,         hydroxy, methoxy, ethoxy, cyano, trifluoromethyl, methyl, ethyl,         isopropyl, —NHC(O)-tert-butyl, —NHC(O)-cyclopropyl, —NHC(O)R¹⁰,         —C(O)NHR¹⁰, —CH₂—N(R⁴)₂, or —NHSO₂CH₃;     -   each occurrence of R^(5aa) is independently chloro, fluoro,         hydroxy, methyl, ethyl, methoxy, ethoxy, trifluoromethyl,         trifluoromethoxy, —C(O)NH₂, —N(C₁₋₆ alkyl)₂, —NHC₁₋₆ alkyl, or         —CO₂H; and     -   each R^(9b) is independently methyl, ethyl, isopropyl, isobutyl,         n-propyl, n-butyl, tert-butyl, —C(O)-methyl, —C(O)-ethyl,         —C(O)-cyclopropyl, —C(O)-tert-butyl, —C(O)-isopropyl, or         —C(O)-cyclobutyl;     -   wherein R¹⁰ and p have the values described herein.

In some embodiments, when X is C(R^(1c))(R^(1d)), G is:

wherein W and Ring C have the values described herein.

The variable W is -L₃-, —CH₂CH₂—NH—, or -L₄-R^(3aa)—V₃—, wherein L₃, R^(3aa), L₄, and V₃ have the values described herein. In some embodiments, W is -L₃-, wherein L₃ has the values described herein. In some embodiments, W is —CH₂CH₂—NH—. In some embodiments, W is -L₄-R^(3aa)—V₃—, wherein L₄, R^(3aa), V₃ have the values described herein. In some embodiments, W is -L₃-, —CH₂CH₂—NH—,

wherein L₃, V₃, and t have the values described herein.

In certain embodiments, W is —CH₂—, —CH₂CH₂—, —CH₂CH₂CH₂—, —CH₂CH₂—NH—,

In certain embodiments, W is —CH₂—, —CH₂CH₂—, W-ii, W-xi, W-xii, W-xxii, W-xxiv, or W-xxv.

The variable L₃ is unsubstituted or substituted C₁₋₃ alkylene chain. In some embodiments, L₃ is —CH₂—, —CH₂CH₂—, or —CH₂CH₂CH₂—. In certain embodiments, L₃ is —CH₂—. In certain embodiments, L₃ is —CH₂CH₂—. In certain embodiments, L₃ is —CH₂CH₂CH₂—.

The variable L₄ is a bond or unsubstituted or substituted C₁₋₃ alkylene chain. In some embodiments, L₄ is a bond, —CH₂—, —CH₂CH₂—, or —CH₂CH₂CH₂—. In certain embodiments, L₄ is a bond. In certain embodiments, L₄ is —CH₂—. In certain embodiments, L₄ is —CH₂CH₂—.

The variable t is 0-2. In some embodiments, t is 0-1. In certain embodiments, t is 0. In certain embodiments, t is 1. In certain embodiments, t is 2.

In some embodiments, when X is N—R^(b), G is:

wherein Y and Ring C have the values described herein.

The variable Y is -L₃-, —CH₂CH₂—NH—, or -L₅-R^(3aa)—V₃—, wherein L₃, R^(3aa), L₅, and V₃ have the values described herein. In some embodiments, Y is -L₃-, wherein L₃ has the values described herein. In some embodiments, Y is —CH₂CH₂—NH—. In some embodiments, Y is -L₅-R^(3aa)—V₃—, wherein L₅, R^(3aa), V₃ have the values described herein. In some embodiments, Y is:

-L₃-, —CH₂CH₂—NH—,

wherein L₅, V₃, and k have the values described herein.

In certain embodiments, W is —CH₂—, —CH₂CH₂—, —CH₂CH₂CH₂—, —CH₂CH₂—NH—,

In certain embodiments, Y is —CH₂—, —CH₂CH₂—, Y-ii, Y-xiii, Y-xiv, or Y-xv.

The variable L₅ is unsubstituted or substituted C₁₋₃ alkylene chain. In some embodiments, L₅ is —CH₂—, —CH₂CH₂—, or —CH₂CH₂CH₂—. In certain embodiments, L₅ is —CH₂—. In certain embodiments, L₅ is —CH₂CH₂—.

The variable k is 1-2. In certain embodiments, k is 1. In certain embodiments, k is 2.

Ring C is a 4-7 membered heterocyclic ring containing one nitrogen atom, wherein the nitrogen atom is not the atom bound to X, and wherein the nitrogen atom in Ring C is substituted with R^(9bb) and Ring C is unsubstituted or substituted by 1-4 occurrences of R^(5b); wherein R^(9bb), X, and R^(5b) have the values described herein. In some embodiments, Ring C is a 4-7 membered heterocyclic ring containing one nitrogen atom, wherein the nitrogen atom is not the atom bound to X, and wherein the nitrogen atom in Ring C is substituted with R^(9bb) and Ring C is unsubstituted or substituted by 1-2 occurrences of R^(5b); wherein R^(9bb), X, and R^(5b) have the values described herein.

In certain embodiments, Ring C is:

wherein Ring C is unsubstituted or substituted with 1 occurrence of R^(5b), wherein R^(9bb) and R^(5b) have the values described herein. In certain embodiments, Ring C is:

wherein R^(9bb), z and R^(5bb) have the values described herein.

The variable V₃ is a bond, —NH—C(O)—, —C(O)—NH—, —NH—S(O)₂—, or —NH—C(O)—NH—. In some embodiments, V₃ is a bond, —C(O)—NH—, or —NH—C(O)—. In certain embodiments, V₃ is a bond. In certain embodiments, V₃ is —NH—C(O)—. In certain embodiments, V₃ is —C(O)—NH—.

The variable R^(3aa) is a 6-membered aromatic ring containing 0-2 nitrogen atoms which is unsubstituted or substituted with 1-2 independent occurrences of R^(4c), wherein R^(4c) has the values described herein. In some embodiments, R^(3aa) is phenyl or pyridyl, each of which is unsubstituted or substituted with 1-2 independent occurrences of R^(4c), wherein R^(4c) has the values described herein. In some embodiments, R^(3aa) is:

wherein each ring is unsubstituted or substituted with 1-2 independent occurrences of R^(4c).

The variable R^(4c) is chloro, fluoro, cyano, hydroxy, methoxy, ethoxy, trifluoromethoxy, trifluoromethyl, methyl, or ethyl. In some embodiments, R^(4c) is chloro, fluoro, methyl or ethyl.

The variable z is 0-1. In some embodiments, z is 0. In some embodiments, z is 1.

Each occurrence of the variable R^(5b) is independently chloro, fluoro, hydroxy, methyl, ethyl, methoxy, ethoxy, trifluoromethyl, trifluoromethoxy, —C(O)NH₂, or —CO₂H. In some embodiments, each occurrence of the variable R^(5b) is independently chloro, fluoro, hydroxy, methyl, or ethyl. In certain embodiments, each occurrence of the variable R^(5b) is methyl.

The variable R^(5bb) is hydrogen or methyl. In some embodiments, R^(5bb) is hydrogen. In some embodiments, R^(5bb) is methyl.

The variable R^(9bb) is hydrogen, unsubstituted C(O)—O—C₁₋₆ aliphatic, unsubstituted C(O)—C₁₋₆ aliphatic, unsubstituted C(O)—C₃₋₁₀ cycloaliphatic, or unsubstituted C₁₋₆ aliphatic. In some embodiments, R^(9bb) is hydrogen, methyl, ethyl, isopropyl, or tert-butoxycarbonyl. In some embodiments, R^(9bb) is methyl, ethyl, or isopropyl. In certain embodiments, R^(9bb) is hydrogen.

In certain embodiments:

R^(2a) is C(O)—NH—OH;

R^(2b) is R¹;

X is N—R^(b);

R^(b) is taken together with R^(1b) to form a double bond; and

R^(a) is G;

wherein R¹ and G have the values described herein.

In certain embodiments:

R^(2a) is C(O)—NH—OH;

R^(2b) is R¹;

X is C(R^(1c))(R^(1d));

R^(1d) is taken together with R^(1b) to form a double bond;

R^(1c) is hydrogen; and

R^(a) is G;

wherein R¹ and G have the values described herein.

In certain embodiments, the compound of formula (I) is represented by:

wherein:

R^(1a′) is hydrogen, fluoro, or C₁₋₄ alkyl;

G is -L₁-R³, or -L₂-V₁—R³; and

V₁ is —O— or —N(R^(4a))—;

wherein L₁, L₂, R¹, R³, and R^(4a) have the values described herein.

In certain such embodiments:

R^(1a′) is hydrogen; and

R¹ is hydrogen.

In certain embodiments, the compound of formula (I) is represented by:

wherein:

R^(1a′) is hydrogen, fluoro, or C₁₋₄ alkyl;

G is -L₁-R³, or -L₂-V₁—R³; and

V₁ is —O— or —N(R^(4a))—;

wherein L₁, L₂, R³ and R^(4a) have the values described herein.

In certain such embodiments:

R^(1a′) is hydrogen; and

R¹ is hydrogen.

In certain embodiments, the compound of formula (I) is represented by:

wherein:

R^(1a′) is hydrogen, fluoro, or C₁₋₄ alkyl;

G is -L₁-R³, or -L₂-V₁—R³; and

V₁ is —O— or —N(R^(4a))—;

wherein L₁, L₂, R¹, R³ and R^(4a) have the values described herein.

In certain such embodiments:

R^(1a′) is hydrogen; and

R¹ is hydrogen.

In certain embodiments, the compound of formula (I) is represented by:

wherein:

R^(a′) is hydrogen, or C₁₋₄ alkyl; and

G¹ is —R³, or -L₁-R³;

wherein L₁ and R³ have the values described herein.

In certain such embodiments:

R^(a′) is hydrogen; and

R¹ is hydrogen.

In certain embodiments, the compound of formula (I) is represented by:

wherein:

R^(1a′) is hydrogen, fluoro, or C₁₋₄ alkyl;

each occurrence of R¹ is independently hydrogen, chloro, fluoro, cyano, hydroxy, methoxy, ethoxy, trifluoromethyl, methyl, or ethyl; and

wherein Ring C and W have the values described herein.

In certain such embodiments:

R^(1a′) is hydrogen; and

R¹ is hydrogen.

In certain embodiments, the compound of formula (I) is represented by:

wherein:

R^(1a′) is hydrogen, fluoro, or C₁₋₄ alkyl;

each occurrence of R¹ is independently hydrogen, chloro, fluoro, cyano, hydroxy, methoxy, ethoxy, trifluoromethyl, methyl, or ethyl; and

wherein Ring C and Y have the values described herein.

In certain such embodiments:

R^(1a′) is hydrogen; and

R¹ is hydrogen.

In certain embodiments, the compound of formula (I) is represented by:

wherein:

R^(1a′) is hydrogen, fluoro, or C₁₋₄ alkyl;

each occurrence of R¹ is independently hydrogen, chloro, fluoro, cyano, hydroxy, methoxy, ethoxy, trifluoromethyl, methyl, or ethyl; and

wherein Ring C and Y have the values described herein.

In certain such embodiments:

R^(1a′) is hydrogen; and

R¹ is hydrogen.

In certain embodiments, the compound of formula (I) is represented by:

wherein:

R^(1a′) is hydrogen, fluoro, or C₁₋₄ alkyl;

each occurrence of R¹ is independently hydrogen, chloro, fluoro, cyano, hydroxy, methoxy, ethoxy, trifluoromethyl, methyl, or ethyl;

R^(9bb) is hydrogen, methyl, ethyl, isopropyl, or tert-butoxycarbonyl;

W is -L₃-, —CH₂CH₂—NH—, W-a, W-b, W-c, W-d, W-e, W-f, and W-g;

Ring C is unsubstituted or substituted with one occurrence of R^(5b); and

z, R^(5b), L₃, V₃, and t have the values described herein.

In certain such embodiments:

R^(5b) is methyl;

R^(1a′) is hydrogen; and

R¹ is hydrogen.

In certain embodiments, the compound of formula (I) is represented by:

wherein:

R^(1a′) is hydrogen, fluoro, or C₁₋₄ alkyl;

each occurrence of R¹ is independently hydrogen, chloro, fluoro, cyano, hydroxy, methoxy, ethoxy, trifluoromethyl, methyl, or ethyl;

R^(9bb) is hydrogen, methyl, ethyl, isopropyl, or tert-butoxycarbonyl;

Y is -L₃-, —CH₂CH₂—NH—, Y-a, Y-b, Y-c, Y-d, Y-e, Y-f, and Y-g;

Ring C is unsubstituted or substituted with one occurrence of R^(5b); and

z, R^(5b), L₅, V₃, and k have the values described herein.

In certain such embodiments:

R^(5b) is methyl;

R^(1a′) is hydrogen; and

R¹ is hydrogen.

In certain embodiments, the compound of formula (I) is represented by:

wherein:

R^(1a′) is hydrogen, fluoro, or C₁₋₄ alkyl;

each occurrence of R¹ is independently hydrogen, chloro, fluoro, cyano, hydroxy, methoxy, ethoxy, trifluoromethyl, methyl, or ethyl;

R^(9bb) is hydrogen, methyl, ethyl, isopropyl, or tert-butoxycarbonyl;

Y is -L₃-, —CH₂CH₂—NH—, Y-a, Y-b, Y-c, Y-d, Y-e, Y-f, and Y-g;

Ring C is unsubstituted or substituted with one occurrence of R^(5b); and

z, R^(5b), L₅, V₃, and k have the values described herein.

In certain such embodiments:

R^(5b) is methyl;

R^(1a′) is hydrogen; and

R¹ is hydrogen.

In certain embodiments, the compound of formula (I) is represented by:

wherein:

R^(1a′) is hydrogen, fluoro, or C₁₋₄ alkyl;

each occurrence of R¹ is independently hydrogen, chloro, fluoro, cyano, hydroxy, methoxy, ethoxy, trifluoromethyl, methyl, or ethyl;

R^(9bb) is hydrogen, methyl, ethyl, isopropyl, or tert-butoxycarbonyl;

W is —CH₂—, —CH₂CH₂—, W-ii, W-xi, W-xii, W-xxii, W-xxiv, or W-xxv;

R^(5bb) is hydrogen or methyl; and

z has the values described herein.

In certain such embodiments:

R^(5bb) is methyl;

z is 1;

R^(1a′) is hydrogen; and

R¹ is hydrogen.

In certain embodiments, the compound of formula (I) is represented by:

wherein:

R^(1a′) is hydrogen, fluoro, or C₁₋₄ alkyl;

each occurrence of R¹ is independently hydrogen, chloro, fluoro, cyano, hydroxy, methoxy, ethoxy, trifluoromethyl, methyl, or ethyl;

R^(9bb) is hydrogen, methyl, ethyl, isopropyl, or tert-butoxycarbonyl;

Y is —CH₂—, —CH₂CH₂—, Y-ii, Y-xiii, Y-xiv, or Y-xv;

R^(5bb) is hydrogen or methyl; and

z has the values described herein.

In certain such embodiments:

R^(5bb) is methyl;

z is 1;

R^(1a′) is hydrogen; and

R¹ is hydrogen.

In certain embodiments, the compound of formula (I) is represented by:

wherein:

R^(1a′) is hydrogen, fluoro, or C₁₋₄ alkyl;

each occurrence of R¹ is independently hydrogen, chloro, fluoro, cyano, hydroxy, methoxy, ethoxy, trifluoromethyl, methyl, or ethyl;

R^(9bb) is hydrogen, methyl, ethyl, isopropyl, or tert-butoxycarbonyl;

Y is —CH₂—, —CH₂CH₂—, Y-ii, Y-xiii, Y-xiv, or Y-xv;

R^(5bb) is hydrogen or methyl; and

z has the values described herein.

In certain such embodiments:

R^(5bb) is methyl;

z is 1;

R^(1a′) is hydrogen; and

R¹ is hydrogen.

In some embodiments, the compound of formula (I) is represented by formulas:

wherein:

R^(1a′) is hydrogen, fluoro, or C₁₋₄ alkyl;

G is -L₁-R³, or -L₂-V₁—R³;

V₁ is —O— or —N(R^(4a))—;

L₁ is —CH₂—, —CH₂CH₂—, or —CH₂CH₂CH₂—; and

L₂ is —CH₂CH₂— or —CH₂CH₂CH₂—;

wherein R³ and R^(4a) have the values described herein.

In certain such embodiments, the compound of formula (I) is represented by formula (V-a-i-a). In certain such embodiments, the compound of formula (I) is represented by formula (V-a-ii-a). In certain such embodiments, the compound of formula (I) is represented by formula (V-b-i-a). In certain such embodiments, the compound of formula (I) is represented by formula (V-b-ii-a).

In certain such embodiments, the compound of formula (I) is represented by formula (V-a-i-a) wherein R^(1a′) is hydrogen and R^(4a) is hydrogen. In certain such embodiments, the compound of formula (I) is represented by formula (V-a-ii-a) wherein R^(1a′) is hydrogen and R^(4a) is hydrogen. In certain such embodiments, the compound of formula (I) is represented by formula (V-b-i-a) wherein R^(1a′) is hydrogen and R^(4a) is hydrogen. In certain such embodiments, the compound of formula (I) is represented by formula (V-b-ii-a) wherein R^(1a′) is hydrogen and R^(4a) is hydrogen.

In some embodiments, the compound of formula (I) is represented by formulas:

wherein:

R^(a′) is hydrogen, or C₁₋₄ alkyl;

G¹ is —R³, or -L₁-R³; and

L₁ is —CH₂—, —CH₂CH₂—, or —CH₂CH₂CH₂—;

wherein R³ has the values described herein.

In certain such embodiments, the compound of formula (I) is represented by formula (V-a-i-b). In certain such embodiments, the compound of formula (I) is represented by formula (V-a-ii-b). In certain such embodiments, the compound of formula (I) is represented by formula (V-b-i-b). In certain such embodiments, the compound of formula (I) is represented by formula (V-b-ii-b).

In certain such embodiments, the compound of formula (I) is represented by formula (V-a-i-b) wherein R^(a′) is hydrogen. In certain such embodiments, the compound of formula (I) is represented by formula (V-a-ii-b) wherein R^(a′) is hydrogen. In certain such embodiments, the compound of formula (I) is represented by formula (V-b-i-b) wherein R^(a′) is hydrogen. In certain such embodiments, the compound of formula (I) is represented by formula (V-b-ii-b) wherein R^(a′) is hydrogen.

Representative examples of compounds of formula (I) are shown in Table 1:

The compounds in Table 1 above may also be identified by the following chemical names:

I-1 2-(3,4-dichlorobenzyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-2 N-hydroxy-1-oxo-2-(piperidin-4-ylmethyl)-1,2-dihydroisoquinoline-7-carboxamide I-3 N-hydroxy-2-[3-(4-methoxyphenoxy)propyl]-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-4 3-(diphenylmethyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-5 N-hydroxy-2-(2-naphthylmethyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-6 2-cyclohexyl-N-hydroxy-4-oxo-3-(2-pyridin-2-ylethyl)-3,4-dihydroquinazoline-7- carboxamide I-7 2-(2,6-dichlorobenzyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-8 2-{3-[(2,2-dimethylpropanoyl)amino]propyl}-N-hydroxy-1-oxo-1,2-dihydroisoquinoline- 7-carboxamide I-9 N-hydroxy-3-isopropyl-4-oxo-2-phenyl-3,4-dihydroquinazoline-7-carboxamide I-10 N-hydroxy-2-[2-(3-methyl-1H-pyrazol-1-yl)ethyl]-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-11 N-hydroxy-1-oxo-2-(3-phenylpropyl)-1,2-dihydroisoquinoline-7-carboxamide I-12 N-hydroxy-4-oxo-3-(1-phenylethyl)-3,4-dihydroquinazoline-6-carboxamide I-13 2-(1-ethyl-1H-pyrazol-5-yl)-N-hydroxy-4-oxo-3-[4-(trifluoromethyl)benzyl]-3,4- dihydroquinazoline-7-carboxamide I-14 N-hydroxy-1-oxo-2-[3-(trifluoromethoxy)benzyl]-1,2-dihydroisoquinoline-7-carboxamide I-15 N-hydroxy-2-(isopropylamino)-3-methyl-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-16 N-hydroxy-4-oxo-3-[3-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-7-carboxamide I-17 2-[(3-tert-butylphenoxy)methyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-18 N-hydroxy-2-methyl-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-19 2-(diphenylmethyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-20 2-{3-[3-(benzyloxy)phenoxy]propyl}-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-21 2-[3-(2,3-dihydro-1H-inden-4-yloxy)propyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-22 N-hydroxy-4-oxo-3-(2-phenoxyethyl)-3,4-dihydroquinazoline-7-carboxamide I-23 3-[(2′,6′-dichlorobiphenyl-3-yl)methyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-24 2-(2,3-difluorobenzyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-25 3-(cyclopropylmethyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-26 N-hydroxy-4-oxo-2-quinolin-8-yl-3-[4-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline- 7-carboxamide I-27 N-hydroxy-2-{2-[2-(2-methyl-1,3-thiazol-4-yl)phenoxy]ethyl}-1-oxo-1,2- dihydroisoquinoline-7-carboxamide I-28 3-[(2′-chlorobiphenyl-3-yl)methyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-29 N-hydroxy-2-[(2-methylphenoxy)methyl]-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-30 N-hydroxy-4-oxo-3-[4-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-6-carboxamide I-31 2-[3-(benzyloxy)benzyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-32 N-hydroxy-3-[(4′-isopropylbiphenyl-3-yl)methyl]-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-33 2-(3,5-dimethylbenzyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-34 N-hydroxy-2-{3-[(4-methoxyphenyl)amino]propyl}-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-35 N-hydroxy-2-(2-methylbenzyl)-4-oxo-3-[4-(trifluoromethyl)benzyl]-3,4- dihydroquinazoline-7-carboxamide I-36 N-hydroxy-4-oxo-3-[2-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-6-carboxamide I-37 N-hydroxy-4-oxo-3-{[3′-(trifluoromethoxy)biphenyl-3-yl]methyl}-3,4- dihydroquinazoline-6-carboxamide I-38 N-hydroxy-2-[3-(2-methylphenoxy)propyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-39 N-hydroxy-4-oxo-2-(2-phenylethyl)-3-[4-(trifluoromethyl)benzyl]-3,4- dihydroquinazoline-7-carboxamide I-40 3-(4-chlorophenyl)-N-hydroxy-2-(isopropylamino)-4-oxo-3,4-dihydroquinazoline-7- carboxamide I-41 N-hydroxy-4-oxo-3-(2-piperidin-1-ylethyl)-3,4-dihydroquinazoline-6-carboxamide I-42 2-[3-(2,3-dihydro-1H-inden-5-yloxy)propyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-43 3-(3-chlorobenzyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-44 N-hydroxy-2-(1-methylbutyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-45 2-(2-{(cyclopropylcarbonyl)[3-(1H-pyrazol-1-yl)phenyl]amino}ethyl)-N-hydroxy-1-oxo- 1,2-dihydroisoquinoline-7-carboxamide I-46 N-hydroxy-4-oxo-3-{[3′-(trifluoromethyl)biphenyl-3-yl]methyl}-3,4-dihydroquinazoline- 6-carboxamide I-47 N-hydroxy-3-methyl-4-oxo-2-[(pyridin-4-ylmethyl)amino]-3,4-dihydroquinazoline-7- carboxamide I-48 N-hydroxy-2-[2-(2-methoxyphenoxy)ethyl]-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-49 N-hydroxy-2-[(4-methoxyphenyl)amino]-3-methyl-4-oxo-3,4-dihydroquinazoline-7- carboxamide I-50 2-(2-chloro-4-fluorobenzyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-51 N-hydroxy-2-{3-[2-(methylsulfonyl)phenoxy]propyl}-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-52 N-hydroxy-1-oxo-2-{3-[2-(trifluoromethyl)phenoxy]propyl}-1,2-dihydroisoquinoline-7- carboxamide I-53 2-(cyclohexylmethyl)-N-hydroxy-4-oxo-3-[4-(trifluoromethyl)benzyl]-3,4- dihydroquinazoline-7-carboxamide I-54 2-(3-fluoro-4-methylbenzyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-55 N-hydroxy-4-oxo-3-[3-(trifluoromethoxy)benzyl]-3,4-dihydroquinazoline-6-carboxamide I-56 tert-butyl 4-[({7-[(hydroxyamino)carbonyl]-4-oxo-3,4-dihydroquinazolin-2- yl}methyl)amino]piperidine-1-carboxylate I-57 N-hydroxy-3-[2-(3-methyl-1H-pyrazol-1-yl)ethyl]-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-58 tert-butyl 4-{2-[7-[(hydroxyamino)carbonyl]-1-oxoisoquinolin-2(1H)-yl]ethyl}piperidine- 1-carboxylate I-59 3-(cyclopropylmethyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-60 3-{[3′-(acetylamino)biphenyl-3-yl]methyl}-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-61 N-hydroxy-1-oxo-2-[3-(trifluoromethyl)benzyl]-1,2-dihydroisoquinoline-7-carboxamide I-62 N-hydroxy-1-oxo-2-(4-phenoxybutyl)-1,2-dihydroisoquinoline-7-carboxamide I-63 3-(2-chlorobenzyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-64 2-cyclobutyl-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-65 N-hydroxy-1-oxo-2-(pentafluorobenzyl)-1,2-dihydroisoquinoline-7-carboxamide I-66 2-[(1,3-benzodioxol-5-yloxy)methyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7- carboxamide I-67 3-(1,3-benzothiazol-2-ylmethyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-68 N²-(4-chlorobenzyl)-N⁷-hydroxy-4-oxo-3,4-dihydroquinazoline-2,7-dicarboxamide I-69 N-hydroxy-4-oxo-3-{[4′-(trifluoromethyl)biphenyl-3-yl]methyl}-3,4-dihydroquinazoline- 6-carboxamide I-70 N-hydroxy-2-[(4-methoxyphenyl)amino]-3-methyl-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-71 N-hydroxy-1-oxo-2-{2-[2-(1H-pyrrol-1-yl)phenoxy]ethyl}-1,2-dihydroisoquinoline-7- carboxamide I-72 N-hydroxy-1-oxo-2-{3-[3-(1,2,3-thiadiazol-4-yl)phenoxy]propyl}-1,2- dihydroisoquinoline-7-carboxamide I-73 N-hydroxy-4-oxo-2-phenyl-3-[4-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-7- carboxamide I-74 N-hydroxy-4-oxo-3-(3-phenylpropyl)-3,4-dihydroquinazoline-7-carboxamide I-75 N-hydroxy-1-oxo-2-[4-(trifluoromethyl)benzyl]-1,2-dihydroisoquinoline-7-carboxamide I-76 2-(4-fluorobenzyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-77 N-hydroxy-1-oxo-2-(2-{[3-(trifluoromethyl)benzyl]amino}ethyl)-1,2-dihydroisoquinoline- 7-carboxamide I-78 2-[2,4-bis(trifluoromethyl)benzyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-79 3-{[3′,5′-bis(trifluoromethyl)biphenyl-3-yl]methyl}-N-hydroxy-4-oxo-3,4- dihydroquinazoline-6-carboxamide I-80 3-{[4′-(acetylamino)biphenyl-3-yl]methyl}-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-81 N-hydroxy-2-isobutyl-4-oxo-3-[4-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-7- carboxamide I-82 N-hydroxy-1-oxo-2-[3-(1H-pyrazol-1-yl)benzyl]-1,2-dihydroisoquinoline-7-carboxamide I-83 N-hydroxy-1-oxo-2-(quinolin-8-ylmethyl)-1,2-dihydroisoquinoline-7-carboxamide I-84 2-[(diethylamino)methyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-85 N-hydroxy-2-(2-naphthyl)-4-oxo-3-[4-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-7- carboxamide I-86 2-[(4-chlorobenzyl)amino]-N-hydroxy-4-oxo-3-phenyl-3,4-dihydroquinazoline-7- carboxamide I-87 3-(4-tert-butylbenzyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-88 N-hydroxy-1-oxo-2-[(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)methyl]-1,2- dihydroisoquinoline-7-carboxamide I-89 tert-butyl {3-[7-[(hydroxyamino)carbonyl]-1-oxoisoquinolin-2(1H)-yl]propyl}pyridin-4- ylcarbamate I-90 N-hydroxy-1-oxo-2-{3-[4-(1,2,3-thiadiazol-4-yl)phenoxy]propyl}-1,2- dihydroisoquinoline-7-carboxamide I-91 2-{2-[3,5-bis(trifluoromethyl)phenoxy]ethyl}-N-hydroxy-1-oxo-1,2-dihydroisoquinoline- 7-carboxamide I-92 2-{[(4-chlorobenzyl)amino]methyl}-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7- carboxamide I-93 tert-butyl 4-{[(3-{[7-[(hydroxyamino)carbonyl]-1-oxoisoquinolin-2(1H)- yl]methyl}phenyl)amino]carbonyl}-4-methylpiperidine-1-carboxylate I-94 2-(2-ethylhexyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-95 N-hydroxy-2-[3-(1H-indol-3-yl)propyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-96 2-(2-cyclohexyl-2-phenylethyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-97 N-hydroxy-2-{2-[(4-methoxyphenyl)amino]ethyl}-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-98 2-[3-(4-fluorophenoxy)benzyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-99 2-[2-(3,5-dichlorophenoxy)ethyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-100 2-sec-butyl-N-hydroxy-4-oxo-3-[4-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-7- carboxamide I-101 2-[2-(3,5-dimethoxyphenoxy)ethyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-102 N-hydroxy-1-oxo-2-(2,4,6-trifluorobenzyl)-1,2-dihydroisoquinoline-7-carboxamide I-103 2-[3-(4-chlorophenyl)-3-piperidin-4-ylpropyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline- 7-carboxamide I-104 N-hydroxy-4-oxo-3-(2-pyridin-2-ylethyl)-3,4-dihydroquinazoline-6-carboxamide I-105 2-cyclopentyl-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-106 2-cyclopentyl-N-hydroxy-4-oxo-3-[4-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-7- carboxamide I-107 N-hydroxy-2-[(3-methylphenoxy)methyl]-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-108 N-hydroxy-1-oxo-2-(2-{[3-(1H-pyrazol-1-yl)phenyl]amino}ethyl)-1,2- dihydroisoquinoline-7-carboxamide I-109 2-(3-fluorobenzyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-110 N-hydroxy-4-oxo-2-{[3-(trifluoromethyl)phenoxy]methyl}-3,4-dihydroquinazoline-7- carboxamide I-111 3-(3-fluorobenzyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-112 N-hydroxy-4-oxo-3-[(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)methyl]-3,4- dihydroquinazoline-6-carboxamide I-113 2-{2-[(4-chlorophenyl)amino]ethyl}-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-114 N-hydroxy-3-(3-morpholin-4-ylbenzyl)-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-115 3-(4-fluorobenzyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-116 2-{3-[4-(benzyloxy)phenoxy]propyl}-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-117 2-cycloheptyl-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-118 N-hydroxy-1-oxo-2-(3-pyridin-4-ylpropyl)-1,2-dihydroisoquinoline-7-carboxamide I-119 2-(3,5-difluorobenzyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-120 N-hydroxy-2-(3-methylbenzyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-121 N-hydroxy-3-isopropyl-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-122 2-(2-fluorobenzyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-123 N-hydroxy-2,4-dioxo-3-phenyl-1,2,3,4-tetrahydroquinazoline-6-carboxamide I-124 N-hydroxy-4-oxo-3-{[2′-(trifluoromethyl)biphenyl-3-yl]methyl}-3,4-dihydroquinazoline- 6-carboxamide I-125 N-hydroxy-3-[2-(3-morpholin-4-ylphenyl)ethyl]-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-126 3-({3′-[(cyclopropylamino)carbonyl]biphenyl-3-yl}methyl)-N-hydroxy-4-oxo-3,4- dihydroquinazoline-6-carboxamide I-127 3-(3-chlorobenzyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-128 N-hydroxy-4-oxo-3-(3-pyridin-4-ylbenzyl)-3,4-dihydroquinazoline-6-carboxamide I-129 N-hydroxy-2-{3-[4-(1H-imidazol-1-yl)phenoxy]propyl}-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-130 2-(2-ethylbutyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-131 2-[3-(4-chlorophenyl)propyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-132 N-hydroxy-2,3-dimethyl-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-133 N-hydroxy-4-oxo-2-pyridin-3-yl-3-[4-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-7- carboxamide I-134 2-(4-chlorophenyl)-N-hydroxy-4-oxo-3-[4-(trifluoromethyl)benzyl]-3,4- dihydroquinazoline-7-carboxamide I-135 N-hydroxy-3-[3-(methylsulfonyl)benzyl]-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-136 N-hydroxy-3-[3-(2-methoxypyridin-3-yl)benzyl]-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-137 N-hydroxy-2-[3-(1H-indazol-1-yl)benzyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-138 2-(1,2-dimethyl-1H-imidazol-5-yl)-N-hydroxy-4-oxo-3-[4-(trifluoromethyl)benzyl]-3,4- dihydroquinazoline-7-carboxamide I-139 2-[(4-chlorobenzyl)amino]-N-hydroxy-3-methyl-4-oxo-3,4-dihydroquinazoline-7- carboxamide I-140 N-hydroxy-2-[3-(4-methoxyphenyl)propyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-141 N-hydroxy-2-(3-methyl-2-phenylbutyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-142 N-hydroxy-4-oxo-3-[3-(phenylsulfonyl)benzyl]-3,4-dihydroquinazoline-6-carboxamide I-143 N-hydroxy-3-[3-(6-methoxypyridin-3-yl)benzyl]-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-144 2-[(2-chlorophenoxy)methyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-145 2-[(3,5-dichlorophenoxy)methyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7- carboxamide I-146 N-hydroxy-4-oxo-2-[(piperidin-4-ylamino)methyl]-3,4-dihydroquinazoline-7-carboxamide I-147 3-[2,4-bis(trifluoromethyl)benzyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-148 N-hydroxy-2-[(5-methylisoxazol-3-yl)methyl]-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-149 N-hydroxy-2-[2-(2-methylphenoxy)ethyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-150 2-cyclohexyl-N-hydroxy-4-oxo-3-[4-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-7- carboxamide I-151 N-hydroxy-2-{3-[(6-methoxy-2-naphthyl)oxy]propyl}-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-152 N-hydroxy-2-[2-(1H-indol-3-yl)ethyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-153 2-(3-cyclohexylpropyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-154 N-hydroxy-1-oxo-2-phenyl-1,2-dihydroisoquinoline-7-carboxamide I-155 N-hydroxy-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxamide I-156 N-hydroxy-3-methyl-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-157 N-hydroxy-2-(2-methylbenzyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-158 N-hydroxy-2-(2-hydroxyethyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-159 2-{2-[3-(diethylamino)phenoxy]ethyl}-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-160 N-hydroxy-1-oxo-2-{3-[2-(1,2,3-thiadiazol-4-yl)phenoxy]propyl}-1,2- dihydroisoquinoline-7-carboxamide I-161 2-(2-{4-[1-adamantyl]phenoxy}ethyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-162 2-(2-chlorobenzyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-163 2-[3-(benzyloxy)propyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-164 3-[(5-chloro-1-benzothien-3-yl)methyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-165 2-[(4-chlorobenzyl)amino]-N-hydroxy-3-methyl-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-166 N-hydroxy-2-(1-methyl-1H-indol-2-yl)-4-oxo-3-[4-(trifluoromethyl)benzyl]-3,4- dihydroquinazoline-7-carboxamide I-167 N-hydroxy-2-{2-[2-(methylsulfonyl)phenoxy]ethyl}-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-168 N-hydroxy-4-oxo-2-{[2-(trifluoromethyl)phenoxy]methyl}-3,4-dihydroquinazoline-7- carboxamide I-169 N-hydroxy-3-methyl-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-6-carboxamide I-170 N-hydroxy-1-oxo-2-(3-piperidin-1-ylpropyl)-1,2-dihydroisoquinoline-7-carboxamide I-171 N-hydroxy-2-isopropyl-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-172 N-hydroxy-1-oxo-2-[2-(trifluoromethyl)benzyl]-1,2-dihydroisoquinoline-7-carboxamide I-173 2-(3-aminopropyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-174 N-hydroxy-2-[3-(isobutyrylamino)benzyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-175 N-hydroxy-1-oxo-2-{2-[2-(trifluoromethyl)phenoxy]ethyl}-1,2-dihydroisoquinoline-7- carboxamide I-176 N-hydroxy-1-oxo-2-{3-[3-(trifluoromethyl)phenoxy]propyl}-1,2-dihydroisoquinoline-7- carboxamide I-177 3-[(3′-aminobiphenyl-3-yl)methyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-178 N-hydroxy-1-oxo-2-{2-[(phenylsulfonyl)methyl]benzyl}-1,2-dihydroisoquinoline-7- carboxamide I-179 2-(3-chlorophenyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-180 N-hydroxy-4-oxo-3-(2-phenoxyethyl)-3,4-dihydroquinazoline-6-carboxamide I-181 3-[(4′-fluorobiphenyl-3-yl)methyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-182 N-hydroxy-3-[(3′-isopropylbiphenyl-3-yl)methyl]-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-183 N-hydroxy-2-{3-[2-(2-methyl-1,3-thiazol-4-yl)phenoxy]propyl}-1-oxo-1,2- dihydroisoquinoline-7-carboxamide I-184 tert-butyl 4-{[7-[(hydroxyamino)carbonyl]-1-oxoisoquinolin-2(1H)-yl]methyl}piperidine- 1-carboxylate I-185 N-hydroxy-4-oxo-3-[3-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-6-carboxamide I-186 N-hydroxy-2-[4-(methylsulfonyl)benzyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-187 2-(2-chloro-6-fluorobenzyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-188 tert-butyl {3-[7-[(hydroxyamino)carbonyl]-1-oxoisoquinolin-2(1H)-yl]propyl}(4- methoxyphenyl)carbamate I-189 N-hydroxy-1-oxo-2-{2-[4-(1,2,3-thiadiazol-4-yl)phenoxy]ethyl}-1,2-dihydroisoquinoline- 7-carboxamide I-190 N-hydroxy-1-oxo-2-[4-(trifluoromethoxy)benzyl]-1,2-dihydroisoquinoline-7-carboxamide I-191 2-[3-(1,3-benzodioxol-5-yloxy)propyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-192 2-(dimethylamino)-N-hydroxy-4-oxo-3-phenyl-3,4-dihydroquinazoline-7-carboxamide I-193 N-hydroxy-4-oxo-3-(pyridin-2-ylmethyl)-3,4-dihydroquinazoline-6-carboxamide I-194 3-benzyl-N-hydroxy-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxamide I-195 N-hydroxy-2,4-dioxo-3-phenyl-1,2,3,4-tetrahydroquinazoline-7-carboxamide I-196 2-[2-(2,3-dihydro-1H-inden-4-yloxy)ethyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-197 N-hydroxy-2-[3-(4-methylphenoxy)propyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-198 2-(2,5-difluorobenzyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-199 2-amino-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-200 N-hydroxy-3-{3-[(methylsulfonyl)amino]benzyl}-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-201 2-(9H-fluoren-9-yl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-202 2-(3,5-dimethoxybenzyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-203 2-(diethylamino)-N-hydroxy-3-methyl-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-204 2-[2-(2-chlorophenoxy)ethyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-205 tert-butyl 4-{1-(4-chlorophenyl)-3-[7-[(hydroxyamino)carbonyl]-1-oxoisoquinolin-2(1H)- yl]propyl}piperidine-1-carboxylate I-206 2-(3-chlorobenzyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-207 2-(2-aminoethyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-208 2-{3-[(diethylamino)methyl]benzyl}-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-209 3-(4-fluorobenzyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-210 N-hydroxy-2-{[4-(1H-imidazol-1-yl)phenoxy]methyl}-4-oxo-3,4-dihydroquinazoline-7- carboxamide I-211 2-[(5-chloro-1-benzothien-3-yl)methyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-212 N-hydroxy-2-[2-(4-methylphenoxy)ethyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-213 2-(2-{[(4-chlorophenyl)sulfonyl]amino}ethyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline- 7-carboxamide I-214 N-hydroxy-2-isopropyl-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-215 N-hydroxy-2-(3-{[(4-methylpiperidin-4-yl)carbonyl]amino}benzyl)-1-oxo-1,2- dihydroisoquinoline-7-carboxamide I-216 N-hydroxy-3-{2-[3-(methylsulfonyl)phenyl]ethyl}-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-217 2-[2,5-bis(trifluoromethyl)benzyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-218 2-(2-ethoxyethyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-219 2-benzyl-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-220 N-hydroxy-4-oxo-3-[2-(3-pyridin-4-ylphenyl)ethyl]-3,4-dihydroquinazoline-6- carboxamide I-221 N-hydroxy-2-(4-methoxyphenyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-222 2-(2,4-difluorobenzyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-223 N-hydroxy-1-oxo-2-[4-(1H-1,2,4-triazol-1-yl)benzyl]-1,2-dihydroisoquinoline-7- carboxamide I-224 N-hydroxy-1-oxo-2-{1-[2-(trifluoromethyl)phenyl]ethyl}-1,2-dihydroisoquinoline-7- carboxamide I-225 N-hydroxy-2-{[(7-methoxy-2-naphthyl)oxy]methyl}-4-oxo-3,4-dihydroquinazoline-7- carboxamide I-226 3-(2-ethoxyethyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-227 2-[3-(2-chlorophenoxy)propyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-228 N-hydroxy-2-[2-(2-methoxyethoxy)ethyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-229 2-{2-[(4-chlorobenzyl)(4-methoxyphenyl)amino]ethyl}-N-hydroxy-1-oxo-1,2- dihydroisoquinoline-7-carboxamide I-230 3-(3-{2-[(2,2-dimethylpropanoyl)amino]pyridin-3-yl}benzyl)-N-hydroxy-4-oxo-3,4- dihydroquinazoline-6-carboxamide I-231 N-hydroxy-2-{3-[(7-methoxy-2-naphthyl)oxy]propyl}-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-232 N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-233 N-hydroxy-4-oxo-2-{[2-(1H-pyrrol-1-yl)phenoxy]methyl}-3,4-dihydroquinazoline-7- carboxamide I-234 N-hydroxy-2-[(5-methyl-2-phenyl-2H-1,2,3-triazol-4-yl)methyl]-1-oxo-1,2- dihydroisoquinoline-7-carboxamide I-235 N-hydroxy-1-oxo-2-[3-(4-phenoxyphenoxy)propyl]-1,2-dihydroisoquinoline-7- carboxamide I-236 2-[2-(4-chlorophenyl)ethyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-237 N-hydroxy-2-(2-morpholin-4-yl-1,3-thiazol-5-yl)-4-oxo-3-[4-(trifluoromethyl)benzyl]-3,4- dihydroquinazoline-7-carboxamide I-238 3-benzyl-2-[(4-chlorobenzyl)amino]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7- carboxamide I-239 N-hydroxy-4-oxo-3-(3-phenylpropyl)-3,4-dihydroquinazoline-6-carboxamide I-240 N-hydroxy-2-[3-(2-methoxyphenoxy)propyl]-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-241 tert-butyl 4-[({7-[(hydroxyamino)carbonyl]-4-oxo-3,4-dihydroquinazolin-2- yl}carbonyl)amino]piperidine-1-carboxylate I-242 N-hydroxy-3-methyl-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-243 2-{[2-(4-chlorophenyl)ethyl]amino}-N-hydroxy-3-methyl-4-oxo-3,4-dihydroquinazoline- 6-carboxamide I-244 3-({3′-[(dimethylamino)sulfonyl]biphenyl-3-yl}methyl)-N-hydroxy-4-oxo-3,4- dihydroquinazoline-6-carboxamide I-245 tert-butyl {3-[7-[(hydroxyamino)carbonyl]-1-oxoisoquinolin-2(1H)-yl]propyl}carbamate I-246 2-[2-(4-chlorophenoxy)ethyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-247 2-(4-chlorophenyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-248 N-hydroxy-2-[(2-methoxyphenoxy)methyl]-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-249 N-hydroxy-2-{[2-(methylsulfonyl)phenoxy]methyl}-4-oxo-3,4-dihydroquinazoline-7- carboxamide I-250 2-(3-amino-3-oxopropyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-251 N-hydroxy-2-[2-(1-naphthyl)ethyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-252 N-hydroxy-1-oxo-2-(2-phenoxyethyl)-1,2-dihydroisoquinoline-7-carboxamide I-253 2-(2-{bis[3-(trifluoromethyl)benzyl]amino}ethyl)-N-hydroxy-1-oxo-1,2- dihydroisoquinoline-7-carboxamide I-254 N-hydroxy-4-oxo-3-{[4′-(piperidin-1-ylsulfonyl)biphenyl-3-yl]methyl}-3,4- dihydroquinazoline-6-carboxamide I-255 N-hydroxy-2-(2-methylbutyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-256 N-hydroxy-3-isopropyl-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-257 N-hydroxy-2-[2-(4-methoxyphenoxy)ethyl]-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-258 2-{2-[3-(benzyloxy)phenoxy]ethyl}-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-259 N-hydroxy-2-[(5-methyl-3-phenylisoxazol-4-yl)methyl]-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-260 N-hydroxy-4-oxo-2-[3-(trifluoromethyl)phenyl]-3,4-dihydroquinazoline-7-carboxamide I-261 2-(cyclopropylmethyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-262 2-[(4-chlorobenzyl)amino]-3-(4-chlorophenyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline- 7-carboxamide I-263 N-hydroxy-4-oxo-2-phenyl-3-(2-pyridin-2-ylethyl)-3,4-dihydroquinazoline-7- carboxamide I-264 3-benzyl-N-hydroxy-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-6-carboxamide I-265 N-hydroxy-2-[(4-methylphenoxy)methyl]-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-266 tert-butyl (3-{[7-[(hydroxyamino)carbonyl]-1-oxoisoquinolin-2(1H)- yl]methyl}phenyl)carbamate I-267 2-(4-tert-butylbenzyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-268 3-[3-(1-benzothien-2-yl)benzyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-269 N-hydroxy-1-oxo-2-[3-(1H-pyrrol-1-yl)propyl]-1,2-dihydroisoquinoline-7-carboxamide I-270 2-{2-[4-(benzyloxy)phenoxy]ethyl}-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-271 N-hydroxy-2-{2-[4-(1H-imidazol-1-yl)phenoxy]ethyl}-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-272 2-(1,3-benzothiazol-2-ylmethyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-273 N-hydroxy-4-oxo-3-[2-oxo-2-(4-pyrrolidin-1-ylphenyl)ethyl]-3,4-dihydroquinazoline-6- carboxamide I-274 2-[4-(dimethylamino)phenyl]-N-hydroxy-4-oxo-3-[4-(trifluoromethyl)benzyl]-3,4- dihydroquinazoline-7-carboxamide I-275 N-hydroxy-3-(4-methylpentyl)-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-276 3-(2-ethoxyethyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-277 N-hydroxy-1-oxo-2-(2-piperidin-1-ylethyl)-1,2-dihydroisoquinoline-7-carboxamide I-278 N⁷-hydroxy-4-oxo-N²-piperidin-4-yl-3,4-dihydroquinazoline-2,7-dicarboxamide I-279 N-hydroxy-1-oxo-2-(pyridin-2-ylmethyl)-1,2-dihydroisoquinoline-7-carboxamide I-280 3-(4-chlorophenyl)-N-hydroxy-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxamide I-281 N-hydroxy-3-[(3′-methoxybiphenyl-3-yl)methyl]-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-282 N-hydroxy-1-oxo-2-{2-[3-(trifluoromethyl)phenoxy]ethyl}-1,2-dihydroisoquinoline-7- carboxamide I-283 N-hydroxy-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-284 N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-285 N-hydroxy-2-[2-(4-methoxyphenyl)ethyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-286 N-hydroxy-3-methyl-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxamide I-287 N-hydroxy-2-methyl-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-288 3-(4-tert-butylbenzyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-289 N-hydroxy-1-oxo-2-[4-(1H-pyrazol-1-yl)benzyl]-1,2-dihydroisoquinoline-7- carboxamide I-290 2-(2,1,3-benzoxadiazol-5-ylmethyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-291 3-(2-{3′-[(cyclopropylamino)carbonyl]biphenyl-3-yl}ethyl)-N-hydroxy-4-oxo-3,4- dihydroquinazoline-6-carboxamide I-292 2-benzyl-4-bromo-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-293 2-[3,3-bis(4-chlorophenyl)propyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-294 N-hydroxy-3-[2-(isopropylamino)ethyl]-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-295 N-hydroxy-4-oxo-3-{2-[4′-(trifluoromethyl)biphenyl-3-yl]ethyl}-3,4-dihydroquinazoline- 6-carboxamide I-296 N-hydroxy-3-[2-(2′-methylbiphenyl-3-yl)ethyl]-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-297 N-hydroxy-3-[2-(4′-isopropylbiphenyl-3-yl)ethyl]-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-298 2-(2-chlorophenyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-299 N-hydroxy-4-oxo-3-{2-[4′-(piperidin-1-ylsulfonyl)biphenyl-3-yl]ethyl}-3,4- dihydroquinazoline-6-carboxamide I-300 3-[2-(4′-fluorobiphenyl-3-yl)ethyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-301 N-hydroxy-3-[2-(4′-methylbiphenyl-3-yl)ethyl]-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-302 3-{2-[3-(1-benzothien-2-yl)phenyl]ethyl}-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-303 N-hydroxy-3-[2-(4′-methoxybiphenyl-3-yl)ethyl]-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-304 N-hydroxy-3-[2-(3′-methylbiphenyl-3-yl)ethyl]-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-305 N-hydroxy-1-oxo-2-[4-(1H-pyrrol-1-yl)benzyl]-1,2-dihydroisoquinoline-7-carboxamide I-306 N-hydroxy-1-oxo-2-(3-piperidin-4-ylphenyl)-1,2-dihydroisoquinoline-7-carboxamide I-307 2-{2-[3-(1-ethylpiperidin-4-yl)phenyl]ethyl}-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-308 N-hydroxy-2-[3-(2H-indazol-2-yl)benzyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-309 3-(2-{3′-[(dimethylamino)sulfonyl]biphenyl-3-yl}ethyl)-N-hydroxy-4-oxo-3,4- dihydroquinazoline-6-carboxamide I-310 N-hydroxy-1-oxo-2-pyridin-2-yl-1,2-dihydroisoquinoline-7-carboxamide I-311 N-hydroxy-4-oxo-3-{2-[3′-(trifluoromethyl)biphenyl-3-yl]ethyl}-3,4-dihydroquinazoline- 6-carboxamide I-312 N-hydroxy-4-oxo-3-{2-[3′-(trifluoromethoxy)biphenyl-3-yl]ethyl}-3,4- dihydroquinazoline-6-carboxamide I-313 3-[2-(2′,6′-dichlorobiphenyl-3-yl)ethyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-314 3-[2-(2′-chlorobiphenyl-3-yl)ethyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-315 2-[2-(1-ethylpiperidin-4-yl)ethyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-316 3-[2-(3′-chlorobiphenyl-3-yl)ethyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-317 tert-butyl 4-(3-{2-[7-[(hydroxyamino)carbonyl]-1-oxoisoquinolin-2(1H)- yl]ethyl}phenyl)piperidine-1-carboxylate I-318 3-{2-[3-(1-benzothien-3-yl)phenyl]ethyl}-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-319 N-hydroxy-2-[3-(1-methyl-1H-pyrazol-4-yl)benzyl]-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-320 N-hydroxy-3-{2-[3-(2-methoxypyridin-3-yl)phenyl]ethyl}-4-oxo-3,4-dihydroquinazoline- 6-carboxamide I-321 3′-{2-[6-[(hydroxyamino)carbonyl]-4-oxoquinazolin-3(4H)-yl]ethyl}biphenyl-4- carboxylic acid I-322 3-[2-(3′-aminobiphenyl-3-yl)ethyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-323 N-hydroxy-4-oxo-3-{2-[3-(1H-pyrazol-5-yl)phenyl]ethyl}-3,4-dihydroquinazoline-6- carboxamide I-324 N-hydroxy-1-oxo-2-[2-(3-piperidin-4-ylphenyl)ethyl]-1,2-dihydroisoquinoline-7- carboxamide I-325 N-hydroxy-4-oxo-3-{2-[2′-(trifluoromethyl)biphenyl-3-yl]ethyl}-3,4-dihydroquinazoline- 6-carboxamide I-326 tert-butyl 4-{3-[7-[(hydroxyamino)carbonyl]-1-oxoisoquinolin-2(1H)- yl]phenyl}piperidine-1-carboxylate I-327 3-[2-(3-{2-[(2,2-dimethylpropanoyl)amino]pyridin-3-yl}phenyl)ethyl]-N-hydroxy-4-oxo- 3,4-dihydroquinazoline-6-carboxamide I-328 N-hydroxy-1-oxo-2-(3-pyridin-4-ylphenyl)-1,2-dihydroisoquinoline-7-carboxamide I-329 N-hydroxy-3-{2-[3-(6-methoxypyridin-3-yl)phenyl]ethyl}-4-oxo-3,4-dihydroquinazoline- 6-carboxamide I-330 N-hydroxy-4-oxo-2-[4-(trifluoromethyl)phenyl]-3,4-dihydroquinazoline-7-carboxamide I-331 N-hydroxy-4-oxo-3-[2-(3-pyridin-3-ylphenyl)ethyl]-3,4-dihydroquinazoline-6- carboxamide I-332 N-hydroxy-4-oxo-3-(2-{[3-(1H-pyrazol-1-yl)benzyl]amino}ethyl)-3,4- dihydroquinazoline-6-carboxamide I-333 N-hydroxy-3-(2-{3-[(methylsulfonyl)amino]phenyl}ethyl)-4-oxo-3,4-dihydroquinazoline- 6-carboxamide I-334 3-{2-[4′-(acetylamino)biphenyl-3-yl]ethyl}-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-335 N-hydroxy-2-(4-nitrophenyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-336 3-{2-[3-(3,5-dimethylisoxazol-4-yl)phenyl]ethyl}-N-hydroxy-4-oxo-3,4- dihydroquinazoline-6-carboxamide I-337 2-benzyl-N-hydroxy-4-(hydroxymethyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-338 N-hydroxy-3-(2-methyl-1-phenylpropyl)-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-339 N-hydroxy-3-[2-(3′-methoxybiphenyl-3-yl)ethyl]-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-340 3-(3-cyclohexyl-3-phenylpropyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-341 N-hydroxy-3-{2-[3′-(methylsulfonyl)biphenyl-3-yl]ethyl}-4-oxo-3,4-dihydroquinazoline- 6-carboxamide I-342 N-hydroxy-3-[2-(3′-isopropylbiphenyl-3-yl)ethyl]-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-343 N-hydroxy-1-oxo-2-(2-piperidin-4-ylethyl)-1,2-dihydroisoquinoline-7-carboxamide I-344 N-hydroxy-1-oxo-2-(2-pyridin-2-ylethyl)-1,2-dihydroisoquinoline-7-carboxamide I-345 3-[2-(3′,5′-dichlorobiphenyl-3-yl)ethyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-346 2-(2-fluorophenyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-347 3-[2-(2′,6′-difluorobiphenyl-3-yl)ethyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-348 2-[2-(diethylamino)-1,3-thiazol-5-yl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7- carboxamide I-349 N-hydroxy-4-oxo-3-[1-(2-phenoxyethyl)cyclopentyl]-3,4-dihydroquinazoline-6- carboxamide I-350 N-hydroxy-4-oxo-3-[(1-phenoxycyclopentyl)methyl]-3,4-dihydroquinazoline-6- carboxamide I-351 tert-butyl {3-[7-[(hydroxyamino)carbonyl]-1-oxoisoquinolin-2(1H)-yl]phenyl}carbamate I-352 2-(1,2-dimethyl-1H-imidazol-5-yl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7- carboxamide I-353 2-cyclopentyl-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-354 2-benzyl-N-hydroxy-4-[(methylamino)methyl]-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-355 2-{1-[(diethylamino)methyl]cyclopentyl}-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7- carboxamide I-356 N-hydroxy-2-isobutyl-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-357 N-hydroxy-3-(1-methyl-1-phenylethyl)-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-358 2-(4-chlorophenyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-359 N-hydroxy-2-(2-morpholin-4-yl-1,3-thiazol-5-yl)-4-oxo-3,4-dihydroquinazoline-7- carboxamide I-360 2-benzyl-N-hydroxy-4-(methoxymethyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-361 3-(1,1-dimethyl-3-phenoxypropyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-362 2-(cyclohexylmethyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-363 2-(1-ethyl-1H-pyrazol-5-yl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-364 N-hydroxy-2-(1-methyl-1H-indol-2-yl)-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-365 N-hydroxy-4-oxo-2-(5-piperidin-1-yl-2-furyl)-3,4-dihydroquinazoline-7-carboxamide I-366 2-(2,4-dimethylbenzyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-367 2-(2-chlorophenyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-368 N-hydroxy-2-(2-methylbenzyl)-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-369 N-hydroxy-2-(3-{[(4-methylpiperidin-4-yl)carbonyl]amino}phenyl)-1-oxo-1,2- dihydroisoquinoline-7-carboxamide I-370 tert-butyl 4-[({3-[7-[(hydroxyamino)carbonyl]-1-oxoisoquinolin-2(1H)- yl]phenyl}amino)carbonyl]-4-methylpiperidine-1-carboxylate I-371 2-[(3,5-dimethyl-1H-pyrazol-1-yl)methyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7- carboxamide I-372 3-(2,2-dimethyl-3-phenoxypropyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-373 N-hydroxy-2-[2-(5-methyl-2-furyl)ethyl]-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-374 3-[3-(1-ethylpiperidin-4-yl)-3-phenylpropyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-375 N-hydroxy-4-oxo-2-(3-pyridin-4-ylphenyl)-3,4-dihydroquinazoline-7-carboxamide I-376 N-hydroxy-4-oxo-2-pyridin-3-yl-3,4-dihydroquinazoline-7-carboxamide I-377 N-hydroxy-4-oxo-2-(2-phenylethyl)-3,4-dihydroquinazoline-7-carboxamide I-378 4-(aminomethyl)-2-benzyl-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-379 N-hydroxy-2-(4-methoxypyridin-3-yl)-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-380 2-sec-butyl-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-381 2-cyclohexyl-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-382 N-hydroxy-4-oxo-3-(1-phenylcyclopropyl)-3,4-dihydroquinazoline-6-carboxamide I-383 3-(1,1-dimethyl-2-phenoxyethyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-6- carboxamide I-384 2-benzyl-4-[(dimethylamino)methyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-385 2-(2-fluorobenzyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-386 2-(1,3-benzoxazol-2-yl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-387 2-benzyl-N-hydroxy-4-methyl-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-388 2-{2-[(cyclopropylcarbonyl)amino]pyridin-4-yl}-N-hydroxy-1-oxo-1,2- dihydroisoquinoline-7-carboxamide I-389 2-[4-(dimethylamino)phenyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-390 N-hydroxy-4-oxo-3-{[1-(phenoxymethyl)cyclopentyl]methyl}-3,4-dihydroquinazoline-6- carboxamide I-391 N-hydroxy-3-(2-methyl-2-phenoxypropyl)-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-392 N-hydroxy-2-(2-naphthyl)-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-393 N-hydroxy-4-oxo-2-quinolin-8-yl-3,4-dihydroquinazoline-7-carboxamide I-394 2-benzyl-N-hydroxy-4-(methoxymethyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-395 N-hydroxy-2-(4-methoxyphenyl)-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-396 N-hydroxy-4-oxo-2-(3-pyridin-4-ylphenyl)-3,4-dihydroquinazoline-7-carboxamide I-397 2-{2-[(cyclopropylcarbonyl)amino]pyridin-4-yl}-N-hydroxy-1-oxo-1,2- dihydroisoquinoline-7-carboxamide I-398 N-hydroxy-4-oxo-2-pyridin-3-yl-3,4-dihydroquinazoline-7-carboxamide I-399 2-(1-ethyl-1H-pyrazol-5-yl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-400 2-benzyl-N-hydroxy-4-methyl-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-401 N-hydroxy-4-oxo-2-phenyl-3,4-dihydroquinazoline-7-carboxamide I-402 N-hydroxy-2-isobutyl-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-403 2-(1,2-dimethyl-1H-imidazol-5-yl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7- carboxamide I-404 2-(1,3-benzoxazol-2-yl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-405 N-hydroxy-2-(2-naphthyl)-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-406 N-hydroxy-2-(2-methylbenzyl)-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-407 4-(aminomethyl)-2-benzyl-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide I-408 N-hydroxy-4-oxo-2-(2-phenylethyl)-3,4-dihydroquinazoline-7-carboxamide I-409 2-(cyclohexylmethyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-410 N-hydroxy-2-(4-methoxypyridin-3-yl)-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-411 2-(2-fluorobenzyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-412 N-hydroxy-2-[2-(5-methyl-2-furyl)ethyl]-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-413 N-hydroxy-3-(1-methyl-1-phenylethyl)-4-oxo-3,4-dihydroquinazoline-6-carboxamide I-414 2-(2-chlorophenyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-415 N-hydroxy-2-(1-methyl-1H-indol-2-yl)-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-416 2-cyclohexyl-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-417 2-(2,4-dimethylbenzyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-418 2-benzyl-N-hydroxy-4-[(methylamino)methyl]-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-419 2-benzyl-4-[(dimethylamino)methyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7- carboxamide I-420 2-cyclopentyl-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide I-421 N-hydroxy-4-oxo-2-piperidin-4-yl-3,4-dihydroquinazoline-7-carboxamide I-422 N-hydroxy-2-(4-{[(4-methylpiperidin-4-yl)carbonyl]amino}phenyl)-1-oxo-1,2- dihydroisoquinoline-7-carboxamide I-423 N-hydroxy-2-(3-{[(4-methylpiperidin-4-yl)carbonyl]amino}phenyl)-1-oxo-1,2- dihydroisoquinoline-7-carboxamide I-424 N-hydroxy-2-(2-{[(4-methylpiperidin-4-yl)carbonyl]amino}pyridin-4-yl)-1-oxo-1,2- dihydroisoquinoline-7-carboxamide I-425 N-hydroxy-2-(5-{[(4-methylpiperidin-4-yl)carbonyl]amino}pyridin-2-yl)-1-oxo-1,2- dihydroisoquinoline-7-carboxamide I-426 N-hydroxy-2-(6-{[(4-methylpiperidin-4-yl)carbonyl]amino}pyridin-2-yl)-1-oxo-1,2- dihydroisoquinoline-7-carboxamide I-427 N-hydroxy-4-oxo-2-(piperidin-4-ylmethyl)-3,4-dihydroquinazoline-7-carboxamide

4. General Synthetic Methods and Intermediates

The compounds of the present invention can be prepared by methods known to one of ordinary skill in the art and/or by reference to the schemes shown below and the synthetic examples. Exemplary synthetic routes are set forth in Schemes below and in the Examples.

Scheme 1 shows a general route for the conversion of methyl ester i to the corresponding hydroxamate by reaction with the potassium salt of hydroxylamine (Method A; Huang et al., J. Med. Chem. 2009, 52(21):6757) leading to the formation of compounds of formula II. Methyl ester i may be commercially available or synthetically derived as described in the schemes below. It will be appreciated that in the Schemes below where the position of the hydroxamate is undefined it can either be in position (a) or (b) with the other position occupied by an R¹ substituent, wherein R¹ is as defined above. Further, any other substitutable position in the aromatic ring of the scaffold can be filled with an R¹ substituent, wherein R¹ is as defined above.

Scheme 2 shows a general route for the conversion of carboxylic acid iii to the corresponding hydroxamate. Acid iii may be coupled to THP-protected hydroxylamine under standard amide coupling conditions (Method B; Carpino et al., J. Am. Chem. Soc. 1995, 117(19):5401). The THP acetal group may be hydrolyzed under treatment with mild acid (Method C; Bernady et al., J. Org. Chem. 1979, 44(9):1438) to afford hydroxamate ii. Carboxylic acid iii may be commercially available or synthetically derived as described in the schemes below.

Scheme 3 depicts a general method for the preparation of N-alkylated or arylated methyl ester vii from bromide v. Commercially available bromide v may be carbonylated in the presence of carbon monoxide gas, methanol and a suitable palladium catalyst and ligand (Method D; Buchwald et al., J. Org. Chem. 2008, 73: 7102) to afford methyl ester vi. The amide nitrogen may be alkylated by standard nucleophilic substitution of an appropriate alkyl iodide or bromide, in the presence of a suitable base such as potassium carbonate in DMF at elevated temperature (Method E). Amide vi may also be arylated by utilizing a Chan-Lam coupling reaction with a suitable arylboronic acid and copper catalyst or by a an Ullmann condensation reaction with a suitable arylbromide and copper catalyst (Method F; Lam et al., Tetrahedron Lett. 1998, 39: 2941; Sughara et al., Chem. Pharm. Bull. 1997, 45(4): 719). Methyl ester vii may be converted to the hydroxamate using Method A.

Scheme 4 shows a general method for the preparation of N-alkylated methyl ester x from carboxylic acid viii. Methyl ester ix (commercially available or prepared as described) may be synthesized under standard Fischer esterification conditions (Method G). The amide nitrogen in ix may be alkylated by standard nucleophilic substitution of an appropriate alkyl iodide or bromide, in the presence of a suitable base such as potassium carbonate in DMF at elevated temperature (Method E). Methyl ester x may be converted to the hydroxamate using Method A.

Scheme 5 depicts a general method for the preparation of di-substituted methyl ester xv from aryl acid xi. Carboxylic acid xi may be converted to the corresponding acid chloride using standard conditions, such as thionyl chloride and treated with methanol to afford methyl ester xii (Method H). Methyl ester xii may be treated with an appropriately substituted urea in the presence of a palladium catalyst to effect a tandem amination-amidation reaction to afford methyl ester xiii (Method I; Willis et al., Org. Lett. 2006, 8(22): 5089). Chlorination of xiii may be performed under standard conditions, such as phosphorus oxychloride at elevated temperatures to yield the corresponding chloride xiv (Method J). The chloride may be displaced under standard substitution conditions with an appropriate amine, in the presence of a suitable base such as N,N-diisopropylethylamine in isopropanol at elevated temperature (Method K). Methyl ester xiii and xv may both be converted to the hydroxamate using Method A.

Scheme 6 shows an alternative route for the preparation of methyl ester xiii from amine xvi. Amine xvi may be treated with an appropriate isocyanate, in the presence of a suitable base such as triethylamine in dioxane at elevated temperature (Method L; U.S. App. Pub. No. 2000/5710319). Methyl ester xiii may be converted to the hydroxamate using Method A.

Scheme 7 shows an alternative route for the preparation of di-substituted methyl ester xv from amine xvi. Amine xvi may be treated with an appropriate nitrile in the presence of an acid to afford methyl ester xvii (Method M; Bogolubsky et al., J. Comb. Chem. 2008, 10(6): 858). The amide nitrogen in xvii may be alkylated under standard conditions using an appropriate alkyl iodide or bromide, in the presence of a suitable base such as sodium hydride in DMF (Method E). Methyl ester xv may be converted to the hydroxamate using Method A.

Scheme 8 shows an alternative route for the preparation of di-substituted methyl ester xv from acid xviii. Acid xviii may be treated with an amine under standard amide coupling conditions to afford amide xix (Method N). The nitro group in xix may be reduced to amine xx under standard hydrogenation conditions using a palladium catalyst (Method O). Amine xx may be treated with an appropriately substituted aldehyde in the presence of an acid to effect an imine cyclization, followed by oxidation with an oxidant such as manganese oxide to afford methyl ester xv (Method P; Intl. App. Pub. No. WO 07/078,022). Methyl ester xv may be converted to the hydroxamate using Method A.

Scheme 9 depicts a general method for the preparation of methyl ester xxiii. Amine xxi may be treated with chloroacetonitrile in the presence of an acid to afford methyl ester xxii (Method M; Bogolubsky et al., J. Comb. Chem. 2008 10(6): 858). The chloride may be displaced using standard nucleophilic substitution with an appropriate amine, in the presence of a suitable base such as triethylamine in DMF at elevated temperature (Method K). Methyl ester xxiii may be converted to the hydroxamate using Method A.

Scheme 10 shows a general route for the conversion of amine xxiv to carboxylic acid xxv. Amine xxiv may be treated with urea at elevated temperatures to afford carboxylic acid xxv (Method Q; Feng et al., J. Med. Chem. 2007 50(10): 2297). Acid xxv may be converted to the hydroxamate using Methods B and C.

Scheme 11 depicts a general method for the preparation of 4-hydroxymethyl substituted methyl ester xxvi from methyl ester vi. The amide nitrogen may be alkylated by standard nucleophilic substitution of an appropriate alkyl iodide or bromide, in the presence of a suitable base such as potassium carbonate in DMF at elevated temperature (Method E). Methyl ester vii may be substituted at the 4-position via reaction with formaldehyde and acid (Method R; Intl. App. Pub. No. WO 06/067444). Methyl ester xxvi may be converted to the hydroxamate using Method A.

5. Uses, Formulation and Administration

In another aspect, the present invention provides compounds of formulas (I), (II), (III), (IV), (V), or their sub-formulas for use in medicine. As discussed above, the present invention provides compounds and pharmaceutical compositions that are useful as inhibitors of HDAC enzymes, particularly HDAC6, and thus the present invention provides compounds for use in treating proliferative, inflammatory, infectious, neurological or cardiovascular disorders.

The compounds and pharmaceutical compositions of the invention are particularly useful for the treatment of cancer. As used herein, the term “cancer” refers to a cellular disorder characterized by uncontrolled or disregulated cell proliferation, decreased cellular differentiation, inappropriate ability to invade surrounding tissue, and/or ability to establish new growth at ectopic sites. The term “cancer” includes, but is not limited to, solid tumors and bloodborne tumors. The term “cancer” encompasses diseases of skin, tissues, organs, bone, cartilage, blood, and vessels. The term “cancer” further encompasses primary and metastatic cancers.

In some embodiments, therefore, the invention provides the compound of formula (I), or a pharmaceutically acceptable salt thereof, for use in treating cancer. In some embodiments, the invention provides a pharmaceutical composition (as described herein) for the treatment of cancer comprising the compound of formula (I), or a pharmaceutically acceptable salt thereof. In some embodiments, the invention provides the use of the compound of formula (I), or a pharmaceutically acceptable salt thereof, for the preparation of a pharmaceutical composition (as described herein) for the treatment of cancer. In some embodiments, the invention provides the use of an effective amount of the compound of formula (I), or a pharmaceutically acceptable salt thereof, for the treatment of cancer.

Non-limiting examples of solid tumors that can be treated with the disclosed inhibitors include pancreatic cancer; bladder cancer; colorectal cancer; breast cancer, including metastatic breast cancer; prostate cancer, including androgen-dependent and androgen-independent prostate cancer; renal cancer, including, e.g., metastatic renal cell carcinoma; hepatocellular cancer; lung cancer, including, e.g., non-small cell lung cancer (NSCLC), bronchioloalveolar carcinoma (BAC), and adenocarcinoma of the lung; ovarian cancer, including, e.g., progressive epithelial or primary peritoneal cancer; cervical cancer; gastric cancer; esophageal cancer; head and neck cancer, including, e.g., squamous cell carcinoma of the head and neck; melanoma; neuroendocrine cancer, including metastatic neuroendocrine tumors; brain tumors, including, e.g., glioma, anaplastic oligodendroglioma, adult glioblastoma multiforme, and adult anaplastic astrocytoma; bone cancer; and soft tissue sarcoma.

Non-limiting examples of hematologic malignancies that can be treated with the disclosed inhibitors include acute myeloid leukemia (AML); chronic myelogenous leukemia (CML), including accelerated CML and CML blast phase (CML-BP); acute lymphoblastic leukemia (ALL); chronic lymphocytic leukemia (CLL); Hodgkin's disease (HD); non-Hodgkin's lymphoma (NHL), including follicular lymphoma and mantle cell lymphoma; B-cell lymphoma; T-cell lymphoma; multiple myeloma (MM); Waldenstrom's macroglobulinemia; myelodysplastic syndromes (MDS), including refractory anemia (RA), refractory anemia with ringed siderblasts (RARS), (refractory anemia with excess blasts (RAEB), and RAEB in transformation (RAEB-T); and myeloproliferative syndromes.

In some embodiments, compounds of the invention are suitable for the treatment of breast cancer, lung cancer, ovarian cancer, multiple myeloma, acute myeloid leukemia or acute lymphoblastic leukemia.

In other embodiments, compounds of the invention are suitable for the treatment of inflammatory and cardiovascular disorders including, but not limited to, allergies/anaphylaxis, acute and chronic inflammation, rheumatoid arthritis; autoimmunity disorders, thrombosis, hypertension, cardiac hypertrophy, and heart failure.

Accordingly, in another aspect of the present invention, pharmaceutical compositions are provided, wherein these compositions comprise any of the compounds as described herein, and optionally comprise a pharmaceutically acceptable carrier, adjuvant or vehicle. In certain embodiments, these compositions optionally further comprise one or more additional therapeutic agents.

It will also be appreciated that certain of the compounds of present invention can exist in free form for treatment, or where appropriate, as a pharmaceutically acceptable derivative thereof. According to the present invention, a pharmaceutically acceptable derivative includes, but is not limited to, pharmaceutically acceptable prodrugs, salts, esters, salts of such esters, or any other adduct or derivative which upon administration to a patient in need is capable of providing, directly or indirectly, a compound as otherwise described herein, or a metabolite or residue thereof.

As used herein, the term “pharmaceutically acceptable salt” refers to those salts which are, within the scope of sound medical judgement, suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response and the like, and are commensurate with a reasonable benefit/risk ratio. A “pharmaceutically acceptable salt” means any non-toxic salt or salt of an ester of a compound of this invention that, upon administration to a recipient, is capable of providing, either directly or indirectly, a compound of this invention or an inhibitorily active metabolite or residue thereof. As used herein, the term “inhibitorily active metabolite or residue thereof” means that a metabolite or residue thereof is also an inhibitor of HDAC6.

Pharmaceutically acceptable salts are well known in the art. For example, S. M. Berge et al., describe pharmaceutically acceptable salts in detail in J. Pharmaceutical Sciences, 1977, 66, 1-19, incorporated herein by reference. Pharmaceutically acceptable salts of the compounds of this invention include those derived from suitable inorganic and organic acids and bases. Examples of pharmaceutically acceptable, nontoxic acid addition salts are salts of an amino group formed with inorganic acids such as hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid and perchloric acid or with organic acids such as acetic acid, oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid or malonic acid or by using other methods used in the art such as ion exchange. Other pharmaceutically acceptable salts include adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, formate, fumarate, glucoheptonate, glycerophosphate, gluconate, hemisulfate, heptanoate, hexanoate, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, p-toluenesulfonate, undecanoate, valerate salts, and the like. Salts derived from appropriate bases include alkali metal, alkaline earth metal, ammonium and N⁺(C₁₋₄alkyl)₄ salts. This invention also envisions the quaternization of any basic nitrogen-containing groups of the compounds disclosed herein. Water or oil-soluble or dispersable products may be obtained by such quaternization. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like. Further pharmaceutically acceptable salts include, when appropriate, nontoxic ammonium, quaternary ammonium, and amine cations formed using counterions such as halide, hydroxide, carboxylate, sulfate, phosphate, nitrate, lower alkyl sulfonate and aryl sulfonate.

As described above, the pharmaceutically acceptable compositions of the present invention additionally comprise a pharmaceutically acceptable carrier, adjuvant, or vehicle, which, as used herein, includes any and all solvents, diluents, or other liquid vehicle, dispersion or suspension aids, surface active agents, isotonic agents, thickening or emulsifying agents, preservatives, solid binders, lubricants and the like, as suited to the particular dosage form desired. Remington's Pharmaceutical Sciences, Sixteenth Edition, E. W. Martin (Mack Publishing Co., Easton, Pa., 1980) discloses various carriers used in formulating pharmaceutically acceptable compositions and known techniques for the preparation thereof. Except insofar as any conventional carrier medium is incompatible with the compounds of the invention, such as by producing any undesirable biological effect or otherwise interacting in a deleterious manner with any other component(s) of the pharmaceutically acceptable composition, its use is contemplated to be within the scope of this invention. Some examples of materials which can serve as pharmaceutically acceptable carriers include, but are not limited to, ion exchangers, alumina, aluminum stearate, lecithin, serum proteins, such as human serum albumin, buffer substances such as phosphates, glycine, sorbic acid, or potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, salts or electrolytes, such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinyl pyrrolidone, polyacrylates, waxes, polyethylene-polyoxypropylene-block polymers, wool fat, sugars such as lactose, glucose and sucrose; starches such as corn starch and potato starch; cellulose and its derivatives such as sodium carboxymethyl cellulose, ethyl cellulose and cellulose acetate; powdered tragacanth; malt; gelatin; talc; excipients such as cocoa butter and suppository waxes; oils such as peanut oil, cottonseed oil; safflower oil; sesame oil; olive oil; corn oil and soybean oil; glycols; such a propylene glycol or polyethylene glycol; esters such as ethyl oleate and ethyl laurate; agar; buffering agents such as magnesium hydroxide and aluminum hydroxide; alginic acid; pyrogen-free water; isotonic saline; Ringer's solution; ethyl alcohol, and phosphate buffer solutions, as well as other non-toxic compatible lubricants such as sodium lauryl sulfate and magnesium stearate, as well as coloring agents, releasing agents, coating agents, sweetening, flavoring and perfuming agents, preservatives and antioxidants can also be present in the composition, according to the judgment of the formulator.

In yet another aspect, a method for treating a proliferative, inflammatory, infectious, neurological or cardiovascular disorder is provided comprising administering an effective amount of a compound, or a pharmaceutical composition to a subject in need thereof. In certain embodiments of the present invention an “effective amount” of the compound or pharmaceutical composition is that amount effective for treating a proliferative, inflammatory, infectious, neurological or cardiovascular disorder, or is that amount effective for treating cancer. In other embodiments, an “effective amount” of a compound is an amount which inhibits binding of HDAC6, and thereby blocks the resulting signaling cascades that lead to the abnormal activity of growth factors, receptor tyrosine kinases, protein serine/threonine kinases, G protein coupled receptors and phospholipid kinases and phosphatases.

The compounds and compositions, according to the method of the present invention, may be administered using any amount and any route of administration effective for treating the disease. The exact amount required will vary from subject to subject, depending on the species, age, and general condition of the subject, the severity of the infection, the particular agent, its mode of administration, and the like. The compounds of the invention are preferably formulated in dosage unit form for ease of administration and uniformity of dosage. The expression “dosage unit form” as used herein refers to a physically discrete unit of agent appropriate for the patient to be treated. It will be understood, however, that the total daily usage of the compounds and compositions of the present invention will be decided by the attending physician within the scope of sound medical judgment. The specific effective dose level for any particular patient or organism will depend upon a variety of factors including the disease being treated and the severity of the disease; the activity of the specific compound employed; the specific composition employed; the age, body weight, general health, sex and diet of the patient; the time of administration, route of administration, and rate of excretion of the specific compound employed; the duration of the treatment; drugs used in combination or coincidental with the specific compound employed, and like factors well known in the medical arts. The term “patient”, as used herein, means an animal, preferably a mammal, and most preferably a human.

The pharmaceutically acceptable compositions of this invention can be administered to humans and other animals orally, rectally, parenterally, intracisternally, intravaginally, intraperitoneally, topically (as by powders, ointments, or drops), bucally, as an oral or nasal spray, or the like, depending on the severity of the infection being treated. In certain embodiments, the compounds of the invention may be administered orally or parenterally at dosage levels of about 0.01 mg/kg to about 50 mg/kg and preferably from about 1 mg/kg to about 25 mg/kg, of subject body weight per day, one or more times a day, to obtain the desired therapeutic effect.

Liquid dosage forms for oral administration include, but are not limited to, pharmaceutically acceptable emulsions, microemulsions, solutions, suspensions, syrups and elixirs. In addition to the active compounds, the liquid dosage forms may contain inert diluents commonly used in the art such as, for example, water or other solvents, solubilizing agents and emulsifiers such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol, dimethylformamide, oils (in particular, cottonseed, groundnut, corn, germ, olive, castor, and sesame oils), glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and fatty acid esters of sorbitan, and mixtures thereof. Besides inert diluents, the oral compositions can also include adjuvants such as wetting agents, emulsifying and suspending agents, sweetening, flavoring, and perfuming agents.

Injectable preparations, for example, sterile injectable aqueous or oleaginous suspensions may be formulated according to the known art using suitable dispersing or wetting agents and suspending agents. The sterile injectable preparation may also be a sterile injectable solution, suspension or emulsion in a nontoxic parenterally acceptable diluent or solvent, for example, as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution, U.S.P. and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil can be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid are used in the preparation of injectables.

The injectable formulations can be sterilized, for example, by filtration through a bacterial-retaining filter, or by incorporating sterilizing agents in the form of sterile solid compositions which can be dissolved or dispersed in sterile water or other sterile injectable medium prior to use.

In order to prolong the effect of a compound of the present invention, it is often desirable to slow the absorption of the compound from subcutaneous or intramuscular injection. This may be accomplished by the use of a liquid suspension of crystalline or amorphous material with poor water solubility. The rate of absorption of the compound then depends upon its rate of dissolution that, in turn, may depend upon crystal size and crystalline form. Alternatively, delayed absorption of a parenterally administered compound form is accomplished by dissolving or suspending the compound in an oil vehicle. Injectable depot forms are made by forming microencapsule matrices of the compound in biodegradable polymers such as polylactide-polyglycolide. Depending upon the ratio of compound to polymer and the nature of the particular polymer employed, the rate of compound release can be controlled. Examples of other biodegradable polymers include poly(orthoesters) and poly(anhydrides). Depot injectable formulations are also prepared by entrapping the compound in liposomes or microemulsions that are compatible with body tissues.

Compositions for rectal or vaginal administration are preferably suppositories which can be prepared by mixing the compounds of this invention with suitable non-irritating excipients or carriers such as cocoa butter, polyethylene glycol or a suppository wax which are solid at ambient temperature but liquid at body temperature and therefore melt in the rectum or vaginal cavity and release the active compound.

Solid dosage forms for oral administration include capsules, tablets, pills, powders, and granules. In such solid dosage forms, the active compound is mixed with at least one inert, pharmaceutically acceptable excipient or carrier such as sodium citrate or dicalcium phosphate and/or a) fillers or extenders such as starches, lactose, sucrose, glucose, mannitol, and silicic acid, b) binders such as, for example, carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidinone, sucrose, and acacia, c) humectants such as glycerol, d) disintegrating agents such as agar—agar, calcium carbonate, potato or tapioca starch, alginic acid, certain silicates, and sodium carbonate, e) solution retarding agents such as paraffin, f) absorption accelerators such as quaternary ammonium compounds, g) wetting agents such as, for example, cetyl alcohol and glycerol monostearate, h) absorbents such as kaolin and bentonite clay, and i) lubricants such as talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, and mixtures thereof. In the case of capsules, tablets and pills, the dosage form may also comprise buffering agents.

Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polyethylene glycols and the like. The solid dosage forms of tablets, dragees, capsules, pills, and granules can be prepared with coatings and shells such as enteric coatings and other coatings well known in the pharmaceutical formulating art. They may optionally contain opacifying agents and can also be of a composition that they release the active ingredient(s) only, or preferentially, in a certain part of the intestinal tract, optionally, in a delayed manner. Examples of embedding compositions that can be used include polymeric substances and waxes. Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polethylene glycols and the like.

The active compounds can also be in micro-encapsulated form with one or more excipients as noted above. The solid dosage forms of tablets, dragees, capsules, pills, and granules can be prepared with coatings and shells such as enteric coatings, release controlling coatings and other coatings well known in the pharmaceutical formulating art. In such solid dosage forms the active compound may be admixed with at least one inert diluent such as sucrose, lactose or starch. Such dosage forms may also comprise, as is normal practice, additional substances other than inert diluents, e.g., tableting lubricants and other tableting aids such a magnesium stearate and microcrystalline cellulose. In the case of capsules, tablets and pills, the dosage forms may also comprise buffering agents. They may optionally contain opacifying agents and can also be of a composition that they release the active ingredient(s) only, or preferentially, in a certain part of the intestinal tract, optionally, in a delayed manner. Examples of embedding compositions that can be used include polymeric substances and waxes.

Dosage forms for topical or transdermal administration of a compound of this invention include ointments, pastes, creams, lotions, gels, powders, solutions, sprays, inhalants or patches. The active component is admixed under sterile conditions with a pharmaceutically acceptable carrier and any needed preservatives or buffers as may be required. Ophthalmic formulation, ear drops, and eye drops are also contemplated as being within the scope of this invention. Additionally, the present invention contemplates the use of transdermal patches, which have the added advantage of providing controlled delivery of a compound to the body. Such dosage forms can be made by dissolving or dispensing the compound in the proper medium. Absorption enhancers can also be used to increase the flux of the compound across the skin. The rate can be controlled by either providing a rate controlling membrane or by dispersing the compound in a polymer matrix or gel.

In some embodiments, a compound of formula (I) or a pharmaceutical composition thereof is administered in conjunction with an anticancer agent. As used herein, the term “anticancer agent” refers to any agent that is administered to a subject with cancer for purposes of treating the cancer. Combination therapy includes administration of the therapeutic agents concurrently or sequentially. Alternatively, the therapeutic agents can be combined into one composition which is administered to the patient.

Non-limiting examples of DNA damaging chemotherapeutic agents include topoisomerase I inhibitors (e.g., irinotecan, topotecan, camptothecin and analogs or metabolites thereof, and doxorubicin); topoisomerase II inhibitors (e.g., etoposide, teniposide, and daunorubicin); alkylating agents (e.g., melphalan, chlorambucil, busulfan, thiotepa, ifosfamide, carmustine, lomustine, semustine, streptozocin, decarbazine, methotrexate, mitomycin C, and cyclophosphamide); DNA intercalators (e.g., cisplatin, oxaliplatin, and carboplatin); DNA intercalators and free radical generators such as bleomycin; and nucleoside mimetics (e.g., 5-fluorouracil, capecitibine, gemcitabine, fludarabine, cytarabine, mercaptopurine, thioguanine, pentostatin, and hydroxyurea).

Chemotherapeutic agents that disrupt cell replication include: paclitaxel, docetaxel, and related analogs; vincristine, vinblastin, and related analogs; thalidomide, lenalidomide, and related analogs (e.g., CC-5013 and CC-4047); protein tyrosine kinase inhibitors (e.g., imatinib mesylate and gefitinib); proteasome inhibitors (e.g., bortezomib); NF-κB inhibitors, including inhibitors of IκB kinase; antibodies which bind to proteins overexpressed in cancers and thereby downregulate cell replication (e.g., trastuzumab, rituximab, cetuximab, and bevacizumab); and other inhibitors of proteins or enzymes known to be upregulated, over-expressed or activated in cancers, the inhibition of which down-regulates cell replication. In certain embodiments, a compound of the invention is administered in conjunction with a proteasome inhibitor.

Another aspect of the invention relates to inhibiting HDAC6, activity in a biological sample or a patient, which method comprises administering to the patient, or contacting said biological sample with a compound of formula (I), or a composition comprising said compound. The term “biological sample”, as used herein, generally includes in vivo, in vitro, and ex vivo materials, and also includes, without limitation, cell cultures or extracts thereof; biopsied material obtained from a mammal or extracts thereof; and blood, saliva, urine, feces, semen, tears, or other body fluids or extracts thereof.

Still another aspect of this invention is to provide a kit comprising separate containers in a single package, wherein the inventive pharmaceutical compounds, compositions and/or salts thereof are used in combination with pharmaceutically acceptable carriers to treat disorders, symptoms and diseases where HDAC6 plays a role.

6. Preparation of Exemplary Compounds Experimental Procedures Definitions

-   ATP adenosine triphosphate -   d day -   DCE dichloroethane -   DCM dichloromethane -   DEA N,N-diethylaniline -   DIPEA diisopropylethyl amine -   DMAP 4-dimethylaminopyridine -   DMF N,N-dimethylformamide -   DMSO dimethylsulfoxide -   Dppf 1,1′-bis(diphenylphosphino)ferrocene -   dppp 1,3-bis(diphenylphosphino)propane -   EDTA ethylenediaminetetraacetic acid -   EtOAc ethyl acetate -   EtOH ethanol -   FA formic acid -   FBS fetal bovine serum -   h hours -   HATU N,N,N′,N′-tetramethyl-o-(7-azabenzotriazole-1-yl)uronium     hexafluorophosphate -   HBTU 2-(7-aza-1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium     hexafluorophosphate -   HEPES N-(2-hydroxyethyl)piperazine-N′-(2-ethanesulfonic acid) -   HRMS high resolution mass spectrum -   IPA isopropyl alcohol -   LC-MS liquid chromatography mass spectrum -   m/z mass to charge -   MTBE methyl tert-butyl ether -   Me methyl -   MEM minimum essential media -   MeOH methanol -   min minutes -   MS mass spectrum -   MWI microwave irradiation -   NMM N-methyl morpholine -   PBS phosphate buffered saline -   rt room temperature -   TEA triethylamine -   TFA trifluoroacetic acid -   TFAA trifluoroacetic anhydride -   TFFH 1,1,3,3-tetramethylfluoroformamidinium hexafluorophosphate -   THF tetrahydrofuran -   THP tetrahydropyran -   TMEDA N,N,N′,N′-tetramethyl-ethane-1,2-diamine -   Xantphos 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene

Analytical Methods

NMR: 1H NMR spectra are run on either a 400 MHz Bruker or 300 MHz Bruker unless otherwise stated.

LC-MS: LC-MS spectra are run using an Agilent 1100 LC interfaced to a micromass Waters® Micromass® Zspray™ Mass Detector (ZMD) using the following gradients:

-   -   Formic Acid (FA): Acetonitrile containing zero to 100 percent         0.1% formic acid in water.     -   Ammonium Acetate (AA): Acetonitrile containing zero to 100         percent 10 mM ammonium acetate in water.

HPLC: Preparative HPLC are conducted using 18×150 mm Sunfire C-18 columns eluting with water-MeCN gradients using a Gilson instrument operated by 322 pumps with the UV/visible 155 detector triggered fraction collection set to between 200 nm and 400 nm. Mass gated fraction collection is conducted on an Agilent 1100 LC/MSD instrument.

Example 1 Methyl 1-oxo-1,2-dihydroisoquinoline-7-carboxylate; Intermediate-1

A solution of 7-bromoisoquinolin-1(2H)-one (2.78 g, 12.4 mmol) in triethylamine (17.29 mL, 124.1 mmol), methanol (70 mL) and DMSO (70 mL) was thoroughly degassed with nitrogen then 1,3-bis(diphenylphosphino)propane (1.02 g, 2.48 mmol) and palladium(II)acetate (0.557 g, 2.48 mmol) were added. After purging the solution four times with CO gas, the reaction mixture was heated at 70° C. for 18 h under 1 atm of CO. The reaction mixture was cooled to rt, methanol was removed before EtOAc (100 mL) and water (50 mL) were added to the remaining DMSO residue. After separation, the organic layer was washed with water and the combined aqueous phases were extracted with EtOAc (100 mL, 2×). The organic phases were then washed with 1N HCl, brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was purified by flash silica gel chromatography (0% to 50% EtOAc/hexanes) to afford methyl 1-oxo-1,2-dihydroisoquinoline-7-carboxylate (2.10 g, 83%). LC-MS: (FA) ES+204; ¹H NMR (400 MHz, CDCl₃) δ 9.56 (s, 1H), 9.08 (d, J=1.7 Hz, 1H), 8.29 (dd, J=8.3, 1.8 Hz, 1H), 7.61 (d, J=8.3 Hz, 1H), 7.21-7.16 (m, 1H), 6.57 (d, J=7.2 Hz, 1H), 3.97 (s, 3H).

Example 2 N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-232

A mixture of hydroxylamine hydrochloride (2.0 g, 29 mmol) in methanol (10 mL) was heated at 90° C. under a dry nitrogen atmosphere until homogeneous. To this heated solution was added a solution of potassium hydroxide (2.85 g, 50.8 mmol) in methanol (6 mL). A precipitate formed on mixing. After heating at 90° C. for 30 minutes, the mixture was cooled to rt and the solids were allowed to settle. The resulting solution was assumed to contain 1.7 M hydroxylamine.potassium salt and was carefully removed by syringe to exclude solids. An aliquot of the above solution (1.0 mL, 1.7 mmol) was added to a solution of methyl 1-oxo-1,2-dihydroisoquinoline-7-carboxylate (32.5 mg, 0.16 mmol) in methanol (1 mL). After stirring for 1 h at rt, excess reagent was quenched by the addition of acetic acid (0.20 mL, 3.52 mmol). The mixture was concentrated to dryness and the residue was twice co-evaporated with toluene. The crude product was purified by preparative HPLC to afford N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide (12 mg, 37%). LC-MS: (FA) ES+205; ¹H NMR (300 MHz, MeOD) δ 8.67 (d, J=1.5 Hz, 1H), 8.06 (dd, J=8.3, 1.9 Hz, 1H), 7.73 (d, J=8.4 Hz, 1H), 7.26 (d, J=7.1 Hz, 1H), 6.70 (d, J=7.3 Hz, 1H).

Example 3 2-benzyl-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-219

Step 1: methyl 2-benzyl-1-oxo-1,2-dihydroisoquinoline-7-carboxylate

To a solution of methyl 1-oxo-1,2-dihydroisoquinoline-7-carboxylate (32.5 mg, 0.16 mmol) in DMF (1.50 mL) was added potassium carbonate (66 mg, 0.48 mmol) and benzyl bromide (38.1 μL, 0.32 mmol). The reaction mixture was heated to 60° C. and stirred for 5 h. The mixture was then cooled to rt and concentrated. Water was added and the reaction mixture was extracted with DCM (5 mL, 3×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated to afford methyl 2-benzyl-1-oxo-1,2-dihydroisoquinoline-7-carboxylate. LC-MS: (FA) ES+294.

Step 2: 2-benzyl-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-219

The title compound was prepared from methyl 2-benzyl-1-oxo-1,2-dihydroisoquinoline-7-carboxylate following the procedure outlined in Example 2 (18 mg, 38%). LC-MS: (FA) ES+295; ¹H NMR (300 MHz, MeOD) δ 8.71 (d, J=1.7 Hz, 1H), 8.06 (dd, J=8.3, 1.9 Hz, 1H), 7.73 (d, J=8.3 Hz, 1H), 7.51 (d, J=7.4 Hz, 1H), 7.36-7.26 (m, 5H), 6.74 (d, J=7.4 Hz, 1H), 5.27 (s, 2H).

Example 4

The following compounds were prepared in a fashion analogous to that described in Example 3 starting from Intermediate-1 and the corresponding alkyl halides.

Compound LC-MS (FA) I-105 ES+ 273 I-287 ES+ 219 I-14 ES+ 379 I-272 ES+ 352 I-206 ES+ 329 I-75 ES+ 363 I-252 ES+ 325 I-267 ES+ 351 I-10 ES+ 313 I-218 ES+ 277 I-88 ES+ 406 I-162 ES+ 329 I-78 ES+ 431 I-211 ES+ 385 I-289 ES+ 361 I-61 ES+ 363 I-261 ES+ 259 I-11 ES+ 323 I-172 ES+ 363 I-279 ES+ 296 I-76 ES+ 313 I-109 ES+ 313 I-213 ES+ 422 I-83 ES+ 346 I-202 ES+ 355 I-171 ES+ 247 I-255 ES+ 275 I-201 ES+ 369 I-44 ES+ 275 I-54 ES+ 327 I-153 ES+ 329 I-130 ES+ 289 I-250 ES+ 276 I-234 ES+ 376 I-198 ES+ 331 I-187 ES+ 347 I-5 ES+ 344 I-157 ES+ 309 I-290 ES+ 337 I-94 ES+ 317 I-163 ES+ 353 I-102 ES+ 349 I-31 ES+ 401 I-119 ES+ 331 I-19 ES+ 371 I-1 ES+ 364 I-122 ES+ 313 I-24 ES+ 331 I-120 ES+ 309 I-50 ES+ 347 I-222 ES+ 331 I-246 ES+ 359 I-190 ES+ 379 I-251 ES+ 359 I-217 ES+ 431 I-228 ES+ 307 I-98 ES+ 405 I-64 ES+ 259 I-33 ES+ 323 I-186 ES+ 373 I-259 ES+ 376 I-65 ES+ 385 I-148 ES+ 300 I-62 ES+ 353 I-178 ES+ 449 I-7 ES+ 364 I-223 ES+ 362 I-152 ES+ 348 I-117 ES+ 301 I-269 ES+ 312 I-236 ES+ 343 I-184 ES+ 402 I-285 ES+ 339 I-58 ES+ 416 I-245 ES+ 362 I-344 ES+ 310

Example 5 N-hydroxy-2-(4-methoxyphenyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-221

Step 1: methyl 2-(4-methoxyphenyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate

To a solution of methyl 1-oxo-1,2-dihydroisoquinoline-7-carboxylate (80 mg, 0.4 mmol) and p-bromoanisole (73.9 μL, 0.6 mmol) in dimethyl sulfoxide (2 mL) was added L-proline (18 mg, 0.16 mmol), potassium carbonate (0.11 g, 0.79 mmol) and copper(I) iodide (15 mg, 0.079 mmol). The reaction mixture was heated to 120° C. and stirred overnight. The mixture was then cooled to rt, water added and extracted with DCM (15 mL, 3×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The crude residue was purified by flash silica gel chromatography (0% to 50% EtOAc/hexanes) to afford methyl 2-(4-methoxyphenyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (30 mg, 20%). LC-MS: (FA) ES+310.

Step 2: N-hydroxy-2-(4-methoxyphenyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-221

The title compound was prepared from methyl 2-(4-methoxyphenyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate following the procedure outlined in Example 2 (8 mg, 30%). LC-MS: (FA) ES+311; ¹H NMR (400 MHz, DMSO) δ 11.46 (s, 1H), 9.13 (s, 1H), 8.65 (d, J=1.7 Hz, 1H), 8.08 (dd, J=8.3, 1.8 Hz, 1H), 7.79 (d, J=8.3 Hz, 1H), 7.51 (d, J=7.4 Hz, 1H), 7.43-7.35 (m, 2H), 7.11-7.03 (m, 2H), 6.74 (d, J=7.4 Hz, 1H), 3.82 (s, 3H).

Example 6 Methyl 4-oxo-3,4-dihydroquinazoline-6-carboxylate; Intermediate-2

To a sealed tube was added 4-oxo-3,4-dihydroquinazoline-6-carboxylic acid (0.88 g, 4.6 mmol), methanol (70 mL) and 4.0 M hydrochloric acid in 1,4-dioxane (4.63 mL, 18.5 mmol). The reaction mixture was heated to 90° C. and stirred overnight. The mixture was then cooled to rt, and concentrated to yield methyl 4-oxo-3,4-dihydroquinazoline-6-carboxylate (0.94 g, quant). LC-MS: (FA) ES+205; ¹H NMR (400 MHz, DMSO) δ 8.65 (d, J=2.1 Hz, 1H), 8.30 (dd, J=8.5, 2.1 Hz, 1H), 8.22 (s, 1H), 7.77 (d, J=8.5 Hz, 1H), 3.88 (s, 3H).

Example 7 N-hydroxy-4-oxo-3,4-dihydroquinazoline-6-carboxamide; Compound I-283

The title compound was prepared from methyl 4-oxo-3,4-dihydroquinazoline-6-carboxylate (43 mg, 0.21 mmol) following the procedure outlined in Example 2 (16 mg, 37%). LC-MS: (FA) ES+206; ¹H NMR (400 MHz, MeOD) δ 8.62 (d, J=2.0 Hz, 1H), 8.18 (dd, J=8.5, 2.1 Hz, 1H), 8.16 (s, 1H), 7.77 (d, J=8.5 Hz, 1H).

Example 8 N-hydroxy-4-oxo-3-[3-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-6-carboxamide; Compound I-185

Step 1: methyl 4-oxo-3-[3-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-6-carboxylate

To a solution of methyl 4-oxo-3,4-dihydroquinazoline-6-carboxylate (30.6 mg, 0.15 mmol) in DMF (2 mL) was added potassium carbonate (41.5 mg, 0.30 mmol) and 3-(trifluoromethyl)benzyl bromide (45.8 μL, 0.30 mmol). The reaction mixture was heated to 60° C. and stirred overnight. The mixture was then cooled to rt and concentrated. Water was added and the reaction mixture was extracted with DCM (5 mL, 3×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated to afford methyl 4-oxo-3-[3-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-6-carboxylate. LC-MS: (FA) ES+363.

Step 2: N-hydroxy-4-oxo-3-[3-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-6-carboxamide; Compound I-185

The title compound was prepared from methyl 4-oxo-3-[3-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-6-carboxylate following the procedure outlined in Example 2 (19 mg, 34%). LC-MS: (FA) ES+364; ¹H NMR (400 MHz, MeOD) δ 8.64 (d, J=1.9 Hz, 1H), 8.58 (s, 1H), 8.18 (dd, J=8.5, 2.1 Hz, 1H), 7.79 (d, J=8.8 Hz, 1H), 7.77 (s, 1H), 7.70-7.53 (m, 3H), 5.34 (s, 2H).

Example 9

The following compounds were prepared in a fashion analogous to that described in Example 8 starting from Intermediate-2 and the corresponding alkyl halides.

Compound LC-MS (FA) I-156 ES+ 220 I-25 ES+ 260 I-239 ES+ 324 I-127 ES+330 I-288 ES+ 352 I-180 ES+ 326 I-121 ES+ 248 I-115 ES+ 314 I-226 ES+ 278 I-273 ES+ 393 I-147 ES+ 432 I-112 ES+ 406 I-67 ES+ 353 I-4 ES+ 372 I-55 ES+ 380 I-164 ES+ 386 I-36 ES+ 364 I-30 ES+ 364 I-104 ES+ 311 I-111 ES+ 314 I-57 ES+ 314 I-63 ES+ 330 I-193 ES+ 297

Example 10 N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide; Compound I-284

The title compound was prepared from methyl 4-oxo-3,4-dihydroquinazoline-7-carboxylate (43 mg, 0.21 mmol) following the procedure outlined in Example 2 (17 mg, 40%). LC-MS: (FA) ES+206; ¹H NMR (400 MHz, MeOD) δ 8.50 (s, 1H), 8.30 (d, J=8.3 Hz, 1H), 8.14 (s, 1H), 8.05 (d, J=1.4 Hz, 1H), 7.87 (dd, J=8.3, 1.6 Hz, 1H).

Example 11 N-hydroxy-4-oxo-3-[3-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-7-carboxamide; Compound I-16

Step 1: methyl 4-oxo-3-[3-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-7-carboxylate

To a solution of methyl 4-oxo-3,4-dihydroquinazoline-7-carboxylate (0.100 g, 0.49 mmol) in DMF (5 mL) was added potassium carbonate (0.135 g, 0.98 mmol) and 3-(trifluoromethyl)benzyl bromide (0.11 mL, 0.74 mmol). The reaction mixture was heated to 60° C. and stirred overnight. The mixture was then cooled to rt and concentrated. Water was added and the reaction mixture was extracted with DCM (15 mL, 3×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated to afford methyl 4-oxo-3-[3-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-7-carboxylate. LC-MS: (FA) ES+363.

Step 2: N-hydroxy-4-oxo-3-[3-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-7-carboxamide; Compound I-16

The title compound was prepared from methyl 4-oxo-3-[3-(trifluoromethyl)benzyl]-3,4-dihydroquinazoline-7-carboxylate following the procedure outlined in Example 2 (87 mg, 70%). LC-MS: (FA) ES+364; ¹H NMR (400 MHz, DMSO) δ 8.69 (s, 1H), 8.19 (d, J=8.3 Hz, 1H), 8.03 (d, J=1.3 Hz, 1H), 7.88 (dd, J=8.3, 1.5 Hz, 1H), 7.81 (s, 1H), 7.70-7.55 (m, 3H), 5.29 (s, 2H).

Example 12

The following compounds were prepared in a fashion analogous to that described in Example 11 starting from Intermediate-3 and the corresponding alkyl halides.

Compound LC-MS (FA) I-242 ES+ 220 I-22 ES+ 326 I-87 ES+ 352 I-74 ES+ 324 I-275 ES+ 290 I-43 ES+ 330 I-256 ES+ 248 I-276 ES+ 278 I-59 ES+ 260 I-209 ES+ 314

Example 13 Dimethyl 2-bromoterephthalate; Intermediate-4

To a round bottom flask was added 2-bromoterephthalic acid (10.0 g, 40.8 mmol) in methanol (120 mL). The suspension was cooled to 0° C. and thionyl chloride (11.9 mL, 163 mmol) was added dropwise. The reaction mixture was allowed to warm to rt and was stirred overnight. The mixture was concentrated, sat. NaHCO₃ was added and extracted with DCM (3×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated to afford dimethyl 2-bromoterephthalate (10.4 g, 93%). LC-MS: (FA) ES+274; ¹H NMR (400 MHz, CDCl₃) δ 8.31 (d, J=1.6 Hz, 1H), 8.00 (dd, J=8.1, 1.6 Hz, 1H), 7.81 (d, J=8.1 Hz, 1H), 3.96 (s, 3H), 3.95 (s, 3H).

Example 14 N-hydroxy-3-methyl-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxamide; Compound I-286

Step 1: methyl 3-methyl-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxylate Intermediate-5

To a solution of dimethyl 2-bromoterephthalate (0.25 g, 0.92 mmol) and methylurea (88.2 mg, 1.19 mmol) in 1,4-dioxane (7 mL) was added cesium carbonate (0.60 g, 1.83 mmol). 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (53.0 mg, 0.092 mmol) was then added followed by tris(dibenzylideneacetone)dipalladium (42 mg, 0.046 mmol). The reaction mixture was heated to 100° C. and stirred for 2 d. The mixture was then cooled to rt and concentrated. Water was added and the remaining solid was filtered. The collected solid was then washed with DCM (3×) to afford methyl 3-methyl-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxylate (0.15 g, 70%). LC-MS: (FA) ES+235; ¹H NMR (400 MHz, DMSO) δ 11.63 (s, 1H), 8.05 (d, J=8.2 Hz, 1H), 7.77 (d, J=1.4 Hz, 1H), 7.71 (dd, J=8.2, 1.5 Hz, 1H), 3.89 (s, 3H), 3.26 (s, 3H).

Step 2: N-hydroxy-3-methyl-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxamide; Compound I-286

A mixture of hydroxylamine hydrochloride (2.0 g, 29 mmol) in methanol (10 mL) was heated at 90° C. under a dry nitrogen atmosphere until homogeneous. To this heated solution was added a solution of potassium hydroxide (2.85 g, 50.8 mmol) in methanol (6 mL). A precipitate formed on mixing. After heating at 90° C. for 30 minutes, the mixture was cooled to rt and the solids were allowed to settle. The resulting solution was assumed to contain 1.7 M hydroxylamine.potassium salt and was carefully removed by syringe to exclude solids. An aliquot of the above solution (2.79 mL, 4.74 mmol) was added to a solution of methyl 3-methyl-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxylate (0.11 g, 0.47 mmol) in methanol (1 mL) and DMF (2 mL). After stirring for 4 h at rt, excess reagent was quenched by the addition of acetic acid (0.27 mL, 4.74 mmol). The mixture was concentrated to dryness and the residue was twice co-evaporated with toluene. The crude product was purified by preparative HPLC to afford N-hydroxy-3-methyl-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxamide (21 mg, 19%). LC-MS: (FA) ES+236; ¹H NMR (400 MHz, DMSO) δ 10.87 (s, 2H), 7.95 (d, J=8.2 Hz, 1H), 7.56 (s, 1H), 7.48 (dd, J=8.2, 1.1 Hz, 1H), 3.25 (s, 3H).

Example 15

The following compounds were prepared in a fashion analogous to that described in Example 14 starting from Intermediate-4 and the corresponding substituted ureas.

Compound LC-MS (FA) I-195 ES+ 298 I-194 ES+ 312

Example 16 3-(4-chlorophenyl)-N-hydroxy-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxamide; Compound I-280

Step 1: methyl 3-(4-chlorophenyl)-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxylate

To a solution of dimethyl 2-aminoterephthalate (1.50 g, 7.2 mmol) in triethylamine (2.50 mL, 18.0 mmol) and 1,4-dioxane (20 mL) was added 1-chloro-4-isocyanatobenzene (1.4 g, 9.3 mmol). The reaction mixture was heated to 90° C. and stirred overnight. The mixture was then cooled to rt and the solid was filtered, then rinsed with ether (2×) to afford methyl 3-(4-chlorophenyl)-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxylate (1.56 g, 66%). LC-MS: (FA) ES+331; ¹H NMR (300 MHz, DMSO) δ 11.77 (s, 1H), 8.07 (d, J=8.2 Hz, 1H), 7.82 (d, J=1.2 Hz, 1H), 7.74 (dd, J=8.2, 1.4 Hz, 1H), 7.56 (d, J=8.6 Hz, 2H), 7.40 (d, J=8.6 Hz, 2H), 3.92 (s, 3H).

Step 2: 3-(4-chlorophenyl)-N-hydroxy-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxamide; Compound I-280

The title compound was prepared from methyl 3-(4-chlorophenyl)-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxylate (0.11 g, 0.33 mmol) following the procedure outlined in Example 14, step 2 (97 mg, 88%). LC-MS: (FA) ES+332; ¹H NMR (300 MHz, DMSO) δ 11.71 (s, 1H), 11.49 (s, 1H), 9.23 (s, 1H), 7.98 (d, J=8.2 Hz, 1H), 7.62-7.46 (m, 4H), 7.39 (d, J=8.7 Hz, 2H).

Example 17 Dimethyl 4-bromoisophthalate; Intermediate-6

Into a round bottom flask was added 4-bromoisophthalic acid (5.0 g, 20.0 mmol) in methanol (75 mL). The suspension was cooled to 0° C. and thionyl chloride (5.06 mL, 69.4 mmol) was added dropwise. The reaction mixture was allowed to warm to rt and was stirred overnight. The mixture was concentrated, sat. NaHCO₃ was added and extracted with DCM (3×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated to afford dimethyl 4-bromoisophthalate (4.20 g, 75%). LC-MS: (FA) ES+274; ¹H NMR (400 MHz, CDCl₃) δ 8.44 (d, J=2.2 Hz, 1H), 7.97 (dd, J=8.4, 2.2 Hz, 1H), 7.76 (d, J=8.4 Hz, 1H), 3.96 (s, 3H), 3.94 (s, 3H).

Example 18 N-hydroxy-3-methyl-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-6-carboxamide; Compound I-169

Step 1: methyl 3-methyl-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-6-carboxylate Intermediate-7

To a solution of dimethyl 4-bromoisophthalate (0.25 g, 0.92 mmol) and methylurea (88.2 mg, 1.19 mmol) in 1,4-dioxane (5 mL) was added cesium carbonate (0.60 g, 1.83 mmol). 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (53.0 mg, 0.092 mmol) was then added followed by tris(dibenzylideneacetone)dipalladium (0) (42 mg, 0.046 mmol). The reaction mixture was heated to 100° C. and stirred for 2 d. The mixture was then cooled to rt and concentrated. Water was added and the remaining solid was filtered. The collected solid was then washed with DCM (3×) to afford methyl 3-methyl-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-6-carboxylate (0.17 g, 80%). LC-MS: (FA) ES+235; ¹H NMR (400 MHz, DMSO) δ 11.81 (s, 1H), 8.47 (d, J=2.0 Hz, 1H), 8.16 (dd, J=8.6, 2.0 Hz, 1H), 7.25 (d, J=8.6 Hz, 1H), 3.87 (s, 3H), 3.26 (s, 3H).

Step 2: N-hydroxy-3-methyl-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-6-carboxamide; Compound I-169

The title compound was prepared from methyl 3-methyl-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-6-carboxylate (0.14 g, 0.60 mmol) following the procedure outlined in Example 14, step 2 (14 mg, 10%). LC-MS: (FA) ES+236; ¹H NMR (400 MHz, DMSO) δ 11.50 (s, 2H), 9.07 (s, 1H), 8.36 (d, J=1.8 Hz, 1H), 8.02 (dd, J=8.5, 1.9 Hz, 1H), 7.21 (d, J=8.5 Hz, 1H), 3.26 (s, 3H).

Example 19

The following compounds were prepared in a fashion analogous to that described in Example 18 starting from Intermediate-6 and the corresponding substituted urea.

Compound LC-MS (FA) I-264 ES+ 312 I-123 ES+ 298

Example 20 Methyl 2-chloro-3-methyl-4-oxo-3,4-dihydroquinazoline-7-carboxylate; Intermediate 8

Into a round bottom flask was added methyl 3-methyl-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxylate (0.48 g, 2.1 mmol) dissolved in phosphoryl chloride (20.0 mL, 214 mmol). N,N-diethylaniline (0.99 mL, 6.2 mmol) was added followed by phosphorus pentachloride (0.22 g, 1.05 mmol). The reaction mixture was heated to 120° C. and stirred for 1 d. The mixture was then cooled to rt and concentrated. The residue was poured over ice and extracted with DCM (3×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The crude residue was purified by flash silica gel chromatography (0% to 50% EtOAc/hexanes) to afford methyl 2-chloro-3-methyl-4-oxo-3,4-dihydroquinazoline-7-carboxylate (0.12 g, 23%). LC-MS: (FA) ES+253; ¹H NMR (400 MHz, CDCl₃) δ 8.31 (d, J=8.4 Hz, 1H), 8.31 (d, J=1.5 Hz, 1H), 8.10 (dd, J=8.4, 1.5 Hz, 1H), 3.98 (s, 3H), 3.78 (s, 3H).

Example 21 2-[(4-chlorobenzyl)amino]-N-hydroxy-3-methyl-4-oxo-3,4-dihydroquinazoline-7-carboxamide; Compound I-139

Step 1: methyl 2-[(4-chlorobenzyl)amino]-3-methyl-4-oxo-3,4-dihydroquinazoline-7-carboxylate

To a suspension of methyl 2-chloro-3-methyl-4-oxo-3,4-dihydroquinazoline-7-carboxylate (70.0 mg, 0.28 mmol) in isopropyl alcohol (3 mL) was added N,N-diisopropylethylamine (0.10 mL, 0.58 mmol) and p-chlorobenzylamine (84.2 μL, 0.69 mmol). The reaction mixture was heated to 100° C. and stirred for 1 h. The mixture was then cooled to rt and concentrated. The residue was purified by flash silica gel chromatography (0% to 5% MeOH/DCM) to afford methyl 2-[(4-chlorobenzyl)amino]-3-methyl-4-oxo-3,4-dihydroquinazoline-7-carboxylate (92 mg, 93%). LC-MS: (FA) ES+358.

Step 2: 2-[(4-chlorobenzyl)amino]-N-hydroxy-3-methyl-4-oxo-3,4-dihydroquinazoline-7-carboxamide; Compound I-139

The title compound was prepared from methyl 2-[(4-chlorobenzyl)amino]-3-methyl-4-oxo-3,4-dihydroquinazoline-7-carboxylate following the procedure outlined in Example 14, step 2 (59 mg, 64%). LC-MS: (FA) ES+359; ¹H NMR (400 MHz, DMSO) δ 10.38 (s, 2H), 7.93 (d, J=8.2 Hz, 1H), 7.79 (t, J=5.6 Hz, 1H), 7.55 (d, J=1.2 Hz, 1H), 7.47-7.41 (m, 3H), 7.37 (d, J=8.5 Hz, 2H), 4.62 (d, J=5.4 Hz, 2H), 3.46 (s, 3H).

Example 22

The following compounds were prepared in a fashion analogous to that described in Example 21 starting from Intermediate-8 and the corresponding substituted amine.

Compound LC-MS (FA) I-47 ES+ 326 I-49 ES+ 341 I-15 ES+ 277

Example 23 Methyl 2-chloro-3-methyl-4-oxo-3,4-dihydroquinazoline-6-carboxylate; Intermediate-9

Into a round bottom flask was added methyl 3-methyl-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-6-carboxylate (1.3 g, 5.3 mmol) dissolved in phosphoryl chloride (20.0 mL, 214 mmol). N,N-diethylaniline (2.6 mL, 16.0 mmol) was added followed by phosphorus pentachloride (0.56 g, 2.7 mmol). The reaction mixture was heated to 120° C. and stirred for 1 d. The mixture was then cooled to rt and concentrated. The residue was poured over ice and extracted with DCM (3×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The crude residue was purified by flash silica gel chromatography (0% to 50% EtOAc/hexanes) to afford methyl 2-chloro-3-methyl-4-oxo-3,4-dihydroquinazoline-6-carboxylate (0.36 g, 26%). LC-MS: (FA) ES+253; ¹H NMR (400 MHz, CDCl₃) δ 8.92 (d, J=2.0 Hz, 1H), 8.38 (dd, J=8.5, 2.0 Hz, 1H), 7.67 (d, J=8.5 Hz, 1H), 3.97 (s, 3H), 3.78 (s, 3H).

Example 24 2-{[2-(4-chlorophenyl)ethyl]amino}-N-hydroxy-3-methyl-4-oxo-3,4-dihydroquinazoline-6-carboxamide; Compound I-243

Step 1: methyl 2-{[2-(4-chlorophenyl)ethyl]amino}-3-methyl-4-oxo-3,4-dihydroquinazoline-6-carboxylate

To a suspension of methyl 2-chloro-3-methyl-4-oxo-3,4-dihydroquinazoline-6-carboxylate (77.0 mg, 0.30 mmol) in isopropyl alcohol (5 mL) was added N,N-diisopropylethylamine (0.11 mL, 0.64 mmol) and 2-(4-chlorophenyl)ethanamine (0.11 mL, 0.76 mmol). The reaction mixture was heated to 100° C. and stirred for 1 h. The mixture was then cooled to rt and concentrated. The residue was purified by flash silica gel chromatography (0% to 5% MeOH/DCM) to afford methyl 2-{[2-(4-chlorophenyl)ethyl]amino}-3-methyl-4-oxo-3,4-dihydroquinazoline-6-carboxylate (106 mg, 94%). LC-MS: (FA) ES+372.

Step 2: 2-{[2-(4-chlorophenyl)ethyl]amino}-N-hydroxy-3-methyl-4-oxo-3,4-dihydroquinazoline-6-carboxamide; Compound I-243

The title compound was prepared from methyl 2-{[2-(4-chlorophenyl)ethyl]amino}-3-methyl-4-oxo-3,4-dihydroquinazoline-6-carboxylate following the procedure outlined in Example 14, step 2 (45 mg, 42%). LC-MS: (FA) ES+373; ¹H NMR (400 MHz, DMSO) δ 11.25 (s, 1H), 9.00 (s, 1H), 8.37 (d, J=2.1 Hz, 1H), 7.94 (dd, J=8.6, 2.2 Hz, 1H), 7.38-7.27 (m, 6H), 3.66-3.57 (m, 2H), 3.37 (s, 3H), 2.99-2.90 (m, 2H).

Example 25

The following compounds were prepared in a fashion analogous to that described in Example 24 starting from Intermediate-9 and the corresponding substituted amine.

Compound LC-MS (FA) I-70 ES+ 341 I-203 ES+ 291 I-165 ES+ 359

Example 26 2-chloromethyl-4-oxo-3,4-dihydro-quinazoline-7-carboxylic acid methyl ester; Intermediate-10

To a solution of dimethyl 2-aminoterephthalate (1.70 g, 8.1 mmol) in 4.0 M hydrochloric acid in 1,4-dioxane (20 mL) was added chloroacetonitrile (0.88 mL, 14 mmol). The reaction mixture was heated to 50° C. and stirred for 3 h. The mixture was then cooled to rt, concentrated and the residue was twice co-evaporated with toluene. Water was added and the solid was filtered to afford methyl 2-(chloromethyl)-4-oxo-3,4-dihydroquinazoline-7-carboxylate (1.8 g, 88%). LC-MS: (FA) ES+253; ¹H NMR (400 MHz, DMSO) δ 12.81 (s, 1H), 8.23 (d, J=8.2 Hz, 1H), 8.14 (d, J=1.1 Hz, 1H), 8.02 (dd, J=8.2, 1.6 Hz, 1H), 4.57 (s, 2H), 3.92 (s, 3H).

Example 27 2-[(diethylamino)methyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide.CH₂O₂; Compound I-84

Step 1: methyl 2-[(diethylamino)methyl]-4-oxo-3,4-dihydroquinazoline-7-carboxylate

To a solution of methyl 2-(chloromethyl)-4-oxo-3,4-dihydroquinazoline-7-carboxylate (160 mg, 0.63 mmol) in DMF (3 mL) was added triethylamine (0.176 mL, 1.27 mmol) and diethylamine (0.33 mL, 3.17 mmol). The reaction mixture was heated to 100° C. and stirred for 3 h. The mixture was then cooled to rt and concentrated. The residue was purified by flash silica gel chromatography (0% to 10% MeOH/DCM) to afford methyl 2-[(diethylamino)methyl]-4-oxo-3,4-dihydroquinazoline-7-carboxylate (0.15 g, 81%). LC-MS: (FA) ES+290.

Step 2: 2-[(diethylamino)methyl]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide.CH₂O₂; Compound I-84

The title compound was prepared from methyl 2-[(diethylamino)methyl]-4-oxo-3,4-dihydroquinazoline-7-carboxylate following the procedure outlined in Example 14, step 2 (76 mg, 45%). The title compound was purified using HPLC conditions that included formic acid and resulted in the isolated of the formic acid salt. LC-MS: (FA) ES+291; ¹H NMR (400 MHz, DMSO) δ 11.47 (s, 1H), 8.15 (d, J=8.2 Hz, 1H), 8.15 (s, 1H), 7.95 (d, J=1.4 Hz, 1H), 7.80 (dd, J=8.2, 1.6 Hz, 1H), 3.56 (s, 2H), 2.62 (q, J=7.1 Hz, 4H), 0.99 (t, J=7.1 Hz, 6H).

Example 28

The following compounds were prepared in a fashion analogous to that described in Example 27 starting from Intermediate-10 and the corresponding substituted amine.

Compound LC-MS (FA) I-92 ES+ 359 I-56 ES+ 418

Example 29 N-hydroxy-4-oxo-2-[(piperidin-4-ylamino)methyl]-3,4-dihydroquinazoline-7-carboxamide.2[HCl]; Compound I-146

To a solution of tert-butyl 4-[({7-[(hydroxyamino)carbonyl]-4-oxo-3,4-dihydroquinazolin-2-yl}methyl)amino]piperidine-1-carboxylate, 1-56 (98 mg, 0.23 mmol) in methylene chloride (3.2 mL) was added 4.0 M hydrochloric acid in 1,4-dioxane (3.2 mL, 12.8 mmol). The reaction mixture was stirred at rt for 2 h. The solid was filtered and washed with DCM to afford N-hydroxy-4-oxo-2-[(piperidin-4-ylamino)methyl]-3,4-dihydroquinazoline-7-carboxamide.2[HCl] (44 mg, 48%). LC-MS: (FA) ES+318; ¹H NMR (300 MHz, DMSO) δ 12.80 (s, 1H), 11.63 (s, 1H), 10.04 (s, 1H), 9.48-9.28 (m, 1H), 9.07 (s, 1H), 8.18 (d, J=8.3 Hz, 1H), 8.07 (d, J=1.2 Hz, 1H), 7.88 (dd, J=8.3, 1.5 Hz, 1H), 4.28 (s, 2H), 3.45-3.26 (m, 3H), 3.02-2.84 (m, 2H), 2.34-2.20 (m, 2H), 2.11-1.88 (m, 2H).

Example 30 N-hydroxy-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxamide; Compound I-155

Step 1: 2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxylic acid

Into a round bottom flask was added 2-aminoterephthalic acid (0.83 g, 4.6 mmol) and urea (2.75 g, 45.8 mmol). The reaction mixture was heated to 160° C. and stirred overnight. The mixture was cooled to rt, water added and the solid was filtered. The solid was then washed with acetic acid to afford 2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxylic acid (0.87 g, 92%). LC-MS: (FA) ES+207.

Step 2: 2,4-dioxo-N-(tetrahydro-2H-pyran-2-yloxy)-1,2,3,4-tetrahydroquinazoline-7-carboxamide; Intermediate-11

A mixture of 2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxylic acid (0.15 g, 0.73 mmol), DMF (2.80 mL), triethylamine (0.30 mL, 2.2 mmol) and fluoro-N,N,N′,N′-tetramethylformamidinium hexafluorophosphate (0.25 g, 0.95 mmol) was stirred for 15 min and O-(tetrahydropyran-2-yl)hydroxylamine (0.10 g, 0.87 mmol) was added. The reaction mixture was stirred at rt for 1 d. Water was added and the mixture was extracted with EtOAc (2×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was purified by flash silica gel chromatography (50% to 100% EtOAc/hexanes) to afford 2,4-dioxo-N-(tetrahydro-2H-pyran-2-yloxy)-1,2,3,4-tetrahydroquinazoline-7-carboxamide (0.15 g, 68%). LC-MS: (FA) ES+306.

Step 3: N-hydroxy-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxamide; Compound I-155

A solution of 2,4-dioxo-N-(tetrahydro-2H-pyran-2-yloxy)-1,2,3,4-tetrahydroquinazoline-7-carboxamide (0.12 g, 0.39 mmol) in THF (1.6 mL), acetic acid (3.2 mL) and water (0.8 mL) was heated at 60° C. for 5 h. The mixture was concentrated to dryness. The residue was purified by preparative HPLC to afford N-hydroxy-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxamide (38 mg, 44%). LC-MS: (FA) ES+222; ¹H NMR (400 MHz, DMSO) δ 11.42 (s, 1H), 11.40 (s, 1H), 11.28 (s, 1H), 9.21 (d, J=1.6 Hz, 1H), 7.92 (d, J=8.2 Hz, 1H), 7.52 (s, 1H), 7.44 (dd, J=8.2, 1.3 Hz, 1H).

Example 31 2-amino-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide; Compound I-199

Step 1: methyl 2-amino-4-oxo-3,4-dihydroquinazoline-7-carboxylate; Intermediate-12

Into a round bottom flask was added dimethyl 2-aminoterephthalate (1.0 g, 4.8 mmol) mixed with carbamimidic chloride-HCl (1.10 g, 9.6 mmol) and dimethyl sulfone (4.5 g, 47.8 mmol). The reaction mixture was heated to 150° C. and stirred overnight. The mixture was cooled to rt, water added and the solid was filtered. The solid was then washed with acetic acid to afford methyl 2-amino-4-oxo-3,4-dihydroquinazoline-7-carboxylate (1.0 g, 95%). LC-MS: (FA) ES+220.

Step 2: 2-amino-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide; Compound I-199

The title compound was prepared from methyl 2-amino-4-oxo-3,4-dihydroquinazoline-7-carboxylate (0.10 g, 0.46 mmol) following the procedure outlined in Example 14, step 2 (38 mg, 40%). LC-MS: (FA) ES+221; ¹H NMR (400 MHz, DMSO) δ 11.34 (s, 1H), 11.08 (s, 1H), 9.13 (s, 1H), 7.90 (d, J=8.2 Hz, 1H), 7.51 (d, J=1.1 Hz, 1H), 7.39 (d, J=8.1 Hz, 1H), 6.48 (s, 2H).

Example 32 N-hydroxy-2-methyl-4-oxo-3,4-dihydroquinazoline-7-carboxamide; Compound I-18

Step 1: methyl 2-methyl-4-oxo-3,4-dihydroquinazoline-7-carboxylate; Intermediate-13

To a solution of dimethyl 2-aminoterephthalate (0.50 g, 2.4 mmol) in 4.0 M hydrochloric acid in 1,4-dioxane (4.8 mL) was added acetonitrile (1.0 mL, 19.0 mmol). The reaction mixture was heated to 50° C. and stirred for 3 h. The mixture was then cooled to rt, concentrated and the residue was twice co-evaporated with toluene. Ether was added and the mixture was extracted with water (2×). The combined aqueous phases were then concentrated to afford methyl 2-methyl-4-oxo-3,4-dihydroquinazoline-7-carboxylate (0.52 g, quant). LC-MS: (FA) ES+219.

Step 2: N-hydroxy-2-methyl-4-oxo-3,4-dihydroquinazoline-7-carboxamide; Compound I-18

The title compound was prepared from methyl 2-methyl-4-oxo-3,4-dihydroquinazoline-7-carboxylate (0.10 g, 0.416 mmol) following the procedure outlined in Example 14, step 2 (52 mg, 50%). LC-MS: (FA) ES+220; ¹H NMR (400 MHz, DMSO) δ 10.33 (s, 3H), 8.11 (d, J=8.2 Hz, 1H), 7.89 (d, J=1.3 Hz, 1H), 7.76 (dd, J=8.2, 1.5 Hz, 1H), 2.36 (s, 3H).

Example 33

The following compounds were prepared in a fashion analogous to that described in Example 32 using the corresponding nitriles.

Compound LC-MS (FA) I-260 ES+ 350 I-214 ES+ 248

Example 34 N-hydroxy-2,3-dimethyl-4-oxo-3,4-dihydroquinazoline-7-carboxamide; Compound I-132

Step 1: methyl 2,3-dimethyl-4-oxo-3,4-dihydroquinazoline-7-carboxylate

To a stirred suspension of sodium hydride (60% in mineral oil, 51 mg, 1.28 mmol) in DMF (5 mL) under an atmosphere of nitrogen was added methyl 2-methyl-4-oxo-3,4-dihydroquinazoline-7-carboxylate (0.14 g, 0.64 mmol) in DMF (2 mL) dropwise. Methyl iodide (80 μL, 1.28 mmol) was then added to the mixture and the resulting solution was stirred at rt overnight. The reaction was quenched with water and extracted with DCM (2×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated to afford methyl 2,3-dimethyl-4-oxo-3,4-dihydroquinazoline-7-carboxylate (70 mg, 50%). LC-MS: (FA) ES+233.

Step 2: N-hydroxy-2,3-dimethyl-4-oxo-3,4-dihydroquinazoline-7-carboxamide; Compound I-132

The title compound was prepared from methyl 2,3-dimethyl-4-oxo-3,4-dihydroquinazoline-7-carboxylate following the procedure outlined in Example 14, step 2 (36 mg, 50%). LC-MS: (FA) ES+234; ¹H NMR (400 MHz, DMSO) δ 8.13 (d, J=8.3 Hz, 1H), 7.90 (d, J=1.3 Hz, 1H), 7.79 (dd, J=8.3, 1.5 Hz, 1H), 3.54 (s, 3H), 2.58 (s, 3H).

Example 35 2-[(4-chlorobenzyl)amino]-3-(4-chlorophenyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide; Compound I-262

Step 1: methyl 2-chloro-3-(4-chlorophenyl)-4-oxo-3,4-dihydroquinazoline-7-carboxylate

Into a round bottom flask was added methyl 3-(4-chlorophenyl)-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxylate (0.28 g, 0.76 mmol) dissolved in phosphoryl chloride (3.2 mL, 34.5 mmol) and N,N-diisopropylethylamine (0.29 mL, 1.7 mmol). The reaction mixture was heated to 120° C. and stirred for 5 h. The mixture was then cooled to rt and concentrated. The residue was poured over ice and the resulting solid was filtered and washed with water to afford methyl 2-chloro-3-(4-chlorophenyl)-4-oxo-3,4-dihydroquinazoline-7-carboxylate (0.26 g, 98%). LC-MS: (FA) ES+350.

Step 2: methyl 2-[(4-chlorobenzyl)amino]-3-(4-chlorophenyl)-4-oxo-3,4-dihydroquinazoline-7-carboxylate

To a suspension of methyl 2-chloro-3-(4-chlorophenyl)-4-oxo-3,4-dihydroquinazoline-7-carboxylate (0.10 g, 0.23 mmol) in isopropyl alcohol (2.5 mL) was added N,N-diisopropylethylamine (84 μL, 0.48 mmol) and p-chlorobenzylamine (70 μL, 0.57 mmol). The reaction mixture was heated to 100° C. and stirred for 1 h. The mixture was then cooled to rt and concentrated. The residue was purified by flash silica gel chromatography (0% to 50% EtOAc/hexanes) to afford methyl 2-[(4-chlorobenzyl)amino]-3-(4-chlorophenyl)-4-oxo-3,4-dihydroquinazoline-7-carboxylate (46 mg, 44%). LC-MS: (FA) ES+456.

Step 3: 2-[(4-chlorobenzyl)amino]-3-(4-chlorophenyl)-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide; Compound I-262

The title compound was prepared from methyl 2-[(4-chlorobenzyl)amino]-3-(4-chlorophenyl)-4-oxo-3,4-dihydroquinazoline-7-carboxylate following the procedure outlined in Example 14, step 2 (20 mg, 50%). LC-MS: (FA) ES+457; ¹H NMR (400 MHz, DMSO) δ 11.36 (s, 1H), 9.14 (s, 1H), 7.93 (d, J=8.2 Hz, 1H), 7.67 (d, J=8.6 Hz, 2H), 7.60 (d, J=1.3 Hz, 1H), 7.51-7.44 (m, 3H), 7.35 (s, 4H), 6.75 (t, J=6.0 Hz, 1H), 4.48 (d, J=5.9 Hz, 2H).

Example 36

The following compounds were prepared in a fashion analogous to that described in Example 35 starting using the corresponding substituted amine.

Compound LC-MS (FA) I-40 ES+ 373

Example 37 2-[(4-chlorobenzyl)amino]-N-hydroxy-4-oxo-3-phenyl-3,4-dihydroquinazoline-7-carboxamide; Compound I-86

Step 1: methyl 2,4-dioxo-3-phenyl-1,2,3,4-tetrahydroquinazoline-7-carboxylate

The title compound was prepared from dimethyl 2-bromoterephthalate (1.50 g, 5.5 mmol) and phenylurea (0.97 g, 7.1 mmol) following the procedure outlined in Example 14, step 1 (1.3 g, 79%). LC-MS: (FA) ES+297.

Step 2: methyl 2-chloro-4-oxo-3-phenyl-3,4-dihydroquinazoline-7-carboxylate

Into a round bottom flask was added methyl 2,4-dioxo-3-phenyl-1,2,3,4-tetrahydroquinazoline-7-carboxylate (0.21 g, 0.70 mmol) dissolved in phosphoryl chloride (3.0 mL, 32.2 mmol) and N,N-diisopropylethylamine (0.27 mL, 1.6 mmol). The reaction mixture was heated to 120° C. and stirred overnight. The mixture was then cooled to rt and concentrated. The residue was poured over ice and the resulting solid was filtered and washed with water to afford methyl 2-chloro-4-oxo-3-phenyl-3,4-dihydroquinazoline-7-carboxylate (0.17 g, 77%). LC-MS: (FA) ES+315.

Step 3: methyl 2-[(4-chlorobenzyl)amino]-4-oxo-3-phenyl-3,4-dihydroquinazoline-7-carboxylate

To a suspension of methyl 2-chloro-4-oxo-3-phenyl-3,4-dihydroquinazoline-7-carboxylate (0.10 g, 0.25 mmol) in isopropyl alcohol (2.8 mL) was added N,N-diisopropylethylamine (93 μL, 0.53 mmol) and p-chlorobenzylamine (77.3 μL, 0.64 mmol). The reaction mixture was heated to 100° C. and stirred for 1 h. The mixture was then cooled to rt and concentrated. The residue was purified by flash silica gel chromatography (0% to 30% EtOAc/hexanes) to afford methyl 2-[(4-chlorobenzyl)amino]-4-oxo-3-phenyl-3,4-dihydroquinazoline-7-carboxylate (30 mg, 30%). LC-MS: (FA) ES+420.

Step 4: 2-[(4-chlorobenzyl)amino]-N-hydroxy-4-oxo-3-phenyl-3,4-dihydroquinazoline-7-carboxamide; Compound I-86

The title compound was prepared from methyl 2-[(4-chlorobenzyl)amino]-4-oxo-3-phenyl-3,4-dihydroquinazoline-7-carboxylate following the procedure outlined in Example 14, step 2 (11 mg, 36%). LC-MS: (FA) ES+421; ¹H NMR (400 MHz, DMSO) δ 11.38 (s, 1H), 9.13 (s, 1H), 7.93 (d, J=8.2 Hz, 1H), 7.65-7.54 (m, 4H), 7.48-7.41 (m, 3H), 7.34 (s, 4H), 6.58 (t, J=6.1 Hz, 1H), 4.49 (d, J=6.0 Hz, 2H).

Example 38

The following compounds were prepared in a fashion analogous to that described in Example 37 starting using the corresponding substituted amine.

Compound LC-MS (FA) I-192 ES+ 325

Example 39 3-benzyl-2-[(4-chlorobenzyl)amino]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide; Compound I-238

Step 1: methyl 3-benzyl-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxylate

The title compound was prepared from dimethyl 2-bromoterephthalate (2.4 g, 8.8 mmol) and benzylurea (1.7 g, 11.4 mmol) following the procedure outlined in Example 14, step 1 (1.8 g, 66%). LC-MS: (FA) ES+311.

Step 2: methyl 3-benzyl-2-chloro-4-oxo-3,4-dihydroquinazoline-7-carboxylate

Into a round bottom flask was added methyl 3-benzyl-2,4-dioxo-1,2,3,4-tetrahydroquinazoline-7-carboxylate (1.0 g, 3.2 mmol) dissolved in phosphoryl chloride (15.0 mL, 161 mmol) and N,N-diisopropylethylamine (1.2 mL, 7.1 mmol). The reaction mixture was heated to 120° C. and stirred for 2 d. The mixture was then cooled to rt and concentrated. The residue was poured over ice and the resulting solid was filtered and washed with water to afford methyl 3-benzyl-2-chloro-4-oxo-3,4-dihydroquinazoline-7-carboxylate (1.0 g, 94%). LC-MS: (FA) ES+329.

Step 3: methyl 3-benzyl-2-[(4-chlorobenzyl)amino]-4-oxo-3,4-dihydroquinazoline-7-carboxylate

To a suspension of methyl 3-benzyl-2-chloro-4-oxo-3,4-dihydroquinazoline-7-carboxylate (0.20 g, 0.37 mmol) in isopropyl alcohol (4 mL) was added N,N-diisopropylethylamine (0.13 mL, 0.77 mmol) and p-chlorobenzylamine (0.11 mL, 0.91 mmol). The reaction mixture was heated to 100° C. and stirred for 1 h. The mixture was then cooled to rt and concentrated. The residue was purified by flash silica gel chromatography (0% to 80% EtOAc/hexanes) to afford methyl 3-benzyl-2-[(4-chlorobenzyl)amino]-4-oxo-3,4-dihydroquinazoline-7-carboxylate (0.12 g, 75%). LC-MS: (FA) ES+434.

Step 4: 3-benzyl-2-[(4-chlorobenzyl)amino]-N-hydroxy-4-oxo-3,4-dihydroquinazoline-7-carboxamide; Compound I-238

The title compound was prepared from methyl 3-benzyl-2-[(4-chlorobenzyl)amino]-4-oxo-3,4-dihydroquinazoline-7-carboxylate following the procedure outlined in Example 14, step 2 (80 mg, 68%). LC-MS: (FA) ES+435; ¹H NMR (400 MHz, DMSO) δ 11.25 (s, 1H), 9.21 (s, 1H), 7.98 (d, J=8.2 Hz, 1H), 7.77 (t, J=5.6 Hz, 1H), 7.57 (d, J=1.3 Hz, 1H), 7.46 (dd, J=8.2, 1.5 Hz, 1H), 7.37-7.25 (m, 5H), 7.22-7.15 (m, 4H), 5.38 (s, 2H), 4.57 (d, J=5.4 Hz, 2H).

Example 40 Tert-butyl 4-[({7-[(hydroxyamino)carbonyl]-4-oxo-3,4-dihydroquinazolin-2-yl}carbonyl)amino]piperidine-1-carboxylate; Compound I-241

Step 1: 2-benzyl 7-methyl 4-oxo-3,4-dihydroquinazoline-2,7-dicarboxylate

To a solution of dimethyl 2-aminoterephthalate (1.70 g, 8.1 mmol) in 4.0 M hydrochloric acid in 1,4-dioxane (20 mL) was added benzyl cyanoformate (2.0 mL, 14 mmol). The reaction mixture was heated to 50° C. and stirred for 3 h. The mixture was then cooled to rt, concentrated and the residue was twice co-evaporated with toluene. Diethyl ether was added and the solid was filtered to afford 2-benzyl 7-methyl 4-oxo-3,4-dihydroquinazoline-2,7-dicarboxylate (2.7 g, 98%). LC-MS: (FA) ES+339.

Step 2: 7-(methoxycarbonyl)-4-oxo-1,2,3,4-tetrahydroquinazoline-2-carboxylic acid

To a solution of 2-benzyl 7-methyl 4-oxo-3,4-dihydroquinazoline-2,7-dicarboxylate (0.70 g, 2.0 mmol) in methanol (7 mL) and ethyl acetate (4 mL) was added 10% palladium on carbon (20 mg). The mixture was purged with H₂ gas (3×) and stirred under an atmosphere of H₂ for 1 d. The reaction mixture was then filtered through Celite, washed with MeOH and concentrated to afford 7-(methoxycarbonyl)-4-oxo-1,2,3,4-tetrahydroquinazoline-2-carboxylic acid (0.48 g, 90%). LC-MS: (FA) ES+251; ¹H NMR (400 MHz, DMSO) δ 7.66 (d, J=8.0 Hz, 1H), 7.52 (s, 1H), 7.17 (d, J=8.2 Hz, 1H), 4.65 (s, 1H), 3.82 (s, 3H).

Step 3: methyl 2-({[1-(tert-butoxycarbonyl)piperidin-4-yl]amino}carbonyl)-4-oxo-1,2,3,4-tetrahydroquinazoline-7-carboxylate

A mixture of 7-(methoxycarbonyl)-4-oxo-1,2,3,4-tetrahydroquinazoline-2-carboxylic acid (0.15 g, 0.6 mmol), DMF (8 mL), N-methylmorpholine (66 μL, 0.6 mmol), N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (0.23 g, 1.2 mmol) and 1-hydroxybenzotriazole (81 mg, 0.6 mmol) was stirred for 15 min and 4-amino-1-Boc-piperidine (144 mg, 0.72 mmol) was added. The reaction mixture was stirred at rt for 1 d. Water was added and the mixture was extracted with EtOAc (2×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was purified by flash silica gel chromatography (0% to 100% EtOAc/DCM) to afford to afford methyl 2-({[1-(tert-butoxycarbonyl)piperidin-4-yl]amino}carbonyl)-4-oxo-1,2,3,4-tetrahydroquinazoline-7-carboxylate (60 mg, 20%). LC-MS: (FA) ES+333.

Step 4: methyl 2-({[1-(tert-butoxycarbonyl)piperidin-4-yl]amino}carbonyl)-4-oxo-3,4-dihydroquinazoline-7-carboxylate

To a solution of methyl 2-({[1-(tert-butoxycarbonyl)piperidin-4-yl]amino}carbonyl)-4-oxo-1,2,3,4-tetrahydroquinazoline-7-carboxylate (60 mg, 0.1 mmol) in chloroform (1.5 mL) was added manganese (IV) oxide (81.4 mg, 0.94 mmol). The reaction mixture was heated to 70° C. and stirred for 3 h. The mixture was cooled to rt, the solid filtered and washed with MeOH to afford methyl 2-({[1-(tert-butoxycarbonyl)piperidin-4-yl]amino}carbonyl)-4-oxo-3,4-dihydroquinazoline-7-carboxylate (60 mg, quant). LC-MS: (FA) ES+331.

Step 5: tert-butyl 4-[({7-[(hydroxyamino)carbonyl]-4-oxo-3,4-dihydroquinazolin-2-yl}carbonyl)amino]piperidine-1-carboxylate; Compound I-241

The title compound was prepared from methyl 2-({[1-(tert-butoxycarbonyl)piperidin-4-yl]amino}carbonyl)-4-oxo-3,4-dihydroquinazoline-7-carboxylate following the procedure outlined in Example 2 (36 mg, 60%). LC-MS: (FA) ES+332; ¹H NMR (300 MHz, DMSO) δ 12.37 (s, 1H), 11.54 (s, 1H), 9.26 (s, 1H), 8.91 (d, J=8.5 Hz, 1H), 8.20 (d, J=8.3 Hz, 1H), 8.15 (s, 1H), 7.89 (d, J=8.4 Hz, 1H), 4.03-3.88 (m, 3H), 2.94-2.76 (m, 2H), 1.81-1.70 (m, 2H), 1.65-1.49 (m, 2H), 1.42 (s, 9H).

Example 41

The following compounds were prepared in a fashion analogous to that described in Example 40.

Compound LC-MS (FA) I-68 ES+ 373

Example 42 N⁷-hydroxy-4-oxo-N²-piperidin-4-yl-3,4-dihydroquinazoline-2,7-dicarboxamide.HCl; Compound I-278

To a solution of tert-butyl 4-[({7-[(hydroxyamino)carbonyl]-4-oxo-3,4-dihydroquinazolin-2-yl}carbonyl)amino]piperidine-1-carboxylate (45 mg, 0.1 mmol) in methylene chloride (1.5 mL) was added 4.0 M hydrochloric acid in 1,4-dioxane (1.50 mL, 6.0 mmol). The reaction mixture was stirred at rt for 2 h. The solid was filtered and washed with DCM to afford N⁷-hydroxy-4-oxo-N²-piperidin-4-yl-3,4-dihydroquinazoline-2,7-dicarboxamide.HCl (34 mg, 89%). LC-MS: (FA) ES+332; ¹H NMR (300 MHz, DMSO) δ 12.42 (s, 1H), 11.55 (s, 1H), 9.28 (s, 1H), 9.11 (d, J=7.7 Hz, 1H), 8.82 (s, 1H), 8.21 (d, J=8.2 Hz, 1H), 8.17 (s, 1H), 7.91 (d, J=8.0 Hz, 1H), 4.13-3.97 (m, 1H), 3.38-3.27 (m, 2H), 3.09-2.95 (m, 2H), 2.02-1.81 (m, 4H).

Example 43

The following compounds were prepared in a fashion analogous to that described in Example 42.

Compound LC-MS (FA) I-2 ES+ 302 I-215 ES+ 435

Example 44 N-hydroxy-2-[3-(4-methoxyphenoxy)propyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-3

Step 1: methyl 2-(3-bromopropyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate; Intermediate-14

To a stirred suspension of sodium hydride (60% in mineral oil, 0.30 g, 7.4 mmol) in DMF (15 mL) under an atmosphere of nitrogen cooled to 0° C. was added methyl 1-oxo-1,2-dihydroisoquinoline-7-carboxylate (1.0 g, 4.9 mmol) in DMF (15 mL) dropwise. The mixture was stirred for 30 mins, then 1,3-dibromopropane (80 μL, 1.28 mmol) was added quickly and the resulting solution was stirred overnight warming to rt slowly. The reaction was quenched with water and extracted with EtOAc (2×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was purified by flash silica gel chromatography (0% to 30% EtOAc/hexanes) to afford methyl 2-(3-bromopropyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.60 g, 38%). LC-MS: (FA) ES+326.

Step 2: methyl 2-[3-(4-methoxyphenoxy)propyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxylate

To a solution of methyl 2-(3-bromopropyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (80 mg, 0.25 mmol) in DMF (2.5 mL) was added potassium carbonate (68 mg, 0.50 mmol) and 4-methoxyphenol (61 mg, 0.50 mmol). The reaction mixture was heated to 40° C. and stirred overnight. The mixture was then cooled to rt, filtered and concentrated to afford methyl 2-[3-(4-methoxyphenoxy)propyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxylate. LC-MS: (FA) ES+368.

Step 3: N-hydroxy-2-[3-(4-methoxyphenoxy)propyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-3

The title compound was prepared from methyl 2-[3-(4-methoxyphenoxy)propyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxylate following the procedure outlined in Example 2 (20 mg, 22%). LC-MS: (FA) ES+369; NMR (400 MHz, MeOD) δ 8.69 (d, J=1.7 Hz, 1H), 8.04 (dd, J=8.3, 1.9 Hz, 1H), 7.71 (d, J=8.3 Hz, 1H), 7.45 (d, J=7.3 Hz, 1H), 6.80 (s, 4H), 6.69 (d, J=7.3 Hz, 1H), 4.26 (t, J=6.8 Hz, 2H), 3.97 (t, J=5.8 Hz, 2H), 3.72 (s, 3H), 2.28-2.20 (m, 2H).

Example 45

The following compounds were prepared in a fashion analogous to that described in Example 44 starting from Intermediate-14 and the corresponding alcohol or amine.

Compound LC-MS (FA) I-191 ES+ 383 I-227 ES+ 373 I-21 ES+ 379 I-129 ES+ 405 I-38 ES+ 353 I-240 ES+ 369 I-160 ES+ 423 I-72 ES+ 423 I-183 ES+ 436 I-90 ES+ 423 I-231 ES+ 419 I-176 ES+ 407 I-197 ES+ 353 I-116 ES+ 445 I-51 ES+ 417 I-52 ES+ 407 I-235 ES+ 431 I-151 ES+ 419 I-42 ES+ 379 I-20 ES+ 445 I-170 ES+ 330

Example 46 N-hydroxy-2-[2-(4-methoxyphenoxy)ethyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-257

Step 1: methyl 2-(2-bromoethyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate; Intermediate-15

To a stirred suspension of sodium hydride (60% in mineral oil, 0.81 g, 20.2 mmol) in DMF (30 mL) under an atmosphere of nitrogen was added methyl 1-oxo-1,2-dihydroisoquinoline-7-carboxylate (2.05 g, 10.1 mmol) in DMF (20 mL) dropwise. The mixture was stirred for 30 mins, then 1,2-dibromoethane (8.7 mL, 101 mmol) was added quickly and the resulting solution was stirred for 2 h. The reaction was quenched with water and extracted with EtOAc (2×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was purified by flash silica gel chromatography (0% to 40% EtOAc/hexanes) to afford methyl 2-(2-bromoethyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (1.20 g, 38%). LC-MS: (FA) ES+311.

Step 2: methyl 2-[2-(4-methoxyphenoxy)ethyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxylate

To a solution of 4-methoxyphenol (74 mg, 0.59 mmol) in THF (2.5 mL) was added potassium tert-butoxide (52 mg, 0.46 mmol). The reaction mixture was stirred at rt for 3 h, then methyl 2-(2-bromoethyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (80 mg, 0.26 mmol) in DMF (2.5 mL) was added and the resulting mixture was stirred at rt overnight. The mixture was then concentrated to afford methyl 2-[2-(4-methoxyphenoxy)ethyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxylate. LC-MS: (FA) ES+354.

Step 3: N-hydroxy-2-[2-(4-methoxyphenoxy)ethyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-257

The title compound was prepared from methyl 2-[2-(4-methoxyphenoxy)ethyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxylate following the procedure outlined in Example 2 (5.5 mg, 6%). LC-MS: (FA) ES+355; ¹H NMR (300 MHz, MeOD) δ 8.71 (d, J=1.8 Hz, 1H), 8.05 (dd, J=8.3, 1.9 Hz, 1H), 7.72 (d, J=8.3 Hz, 1H), 7.53 (d, J=7.4 Hz, 1H), 6.86-6.76 (m, 4H), 6.72 (d, J=7.3 Hz, 1H), 4.42 (t, J=5.1 Hz, 2H), 4.28 (t, J=5.1 Hz, 2H), 3.70 (s, 3H).

Example 47

The following compounds were prepared in a fashion analogous to that described in Example 46 starting from Intermediate-15 and the corresponding alcohols.

Compound LC-MS (FA) I-282 ES+ 393 I-175 ES+ 393 I-71 ES+ 390 I-159 ES+ 396 I-270 ES+ 431 I-161 ES+ 459 I-149 ES+ 339 I-48 ES+ 355 I-258 ES+ 431 I-91 ES+ 461 I-167 ES+ 403 I-271 ES+ 391 I-27 ES+ 422 I-99 ES+ 394 I-204 ES+ 359 I-101 ES+ 385 I-196 ES+ 365 I-212 ES+ 339 I-189 ES+ 409

Example 48 N-hydroxy-4-oxo-2-{[2-(trifluoromethyl)phenoxy]methyl}-3,4-dihydroquinazoline-7-carboxamide; Compound I-168

Step 1: methyl 4-oxo-2-{[2-(trifluoromethyl)phenoxy]methyl}-3,4-dihydroquinazoline-7-carboxylate

To a solution of 2-(trifluoromethyl)phenol (36 mg, 0.22 mmol) in THF (1 mL) was added potassium tert-butoxide (24 mg, 0.22 mmol) and the reaction was stirred at rt for 3 h. Then tetra-n-butylammonium iodide (9 mg, 0.024 mmol), cesium carbonate (78 mg, 0.24 mmol) and methyl 2-(chloromethyl)-4-oxo-3,4-dihydroquinazoline-7-carboxylate (30 mg, 0.12 mmol) in DMF (1 mL) was added. The reaction mixture was stirred at rt for 2 d. The mixture was then concentrated to afford methyl 4-oxo-2-{[2-(trifluoromethyl)phenoxy]methyl}-3,4-dihydroquinazoline-7-carboxylate. LC-MS: (FA) ES+379.

Step 2: N-hydroxy-4-oxo-2-{[2-(trifluoromethyl)phenoxy]methyl}-3,4-dihydroquinazoline-7-carboxamide; Compound I-168

The title compound was prepared from methyl 4-oxo-2-{[2-(trifluoromethyl)phenoxy]methyl}-3,4-dihydroquinazoline-7-carboxylate following the procedure outlined in Example 2 (8 mg, 18%). LC-MS: (FA) ES+380; NMR (400 MHz, MeOD) δ 8.29 (d, J=8.3 Hz, 1H), 8.05 (d, J=1.1 Hz, 1H), 7.87 (dd, J=8.3, 1.5 Hz, 1H), 7.66-7.57 (m, 2H), 7.35 (d, J=8.4 Hz, 1H), 7.15 (t, J=7.6 Hz, 1H), 5.17 (s, 2H).

Example 49

The following compounds were prepared in a fashion analogous to that described in Example 48 starting from Intermediate-10 and the corresponding alcohols.

Compound LC-MS (FA) I-249 ES+ 390 I-233 ES+ 377 I-66 ES+ 356 I-17 ES+ 368 I-110 ES+ 380 I-107 ES+ 326 I-144 ES+ 346 I-210 ES+ 378 I-145 ES+ 381 I-29 ES+ 326 I-225 ES+ 392 I-265 ES+ 326 I-248 ES+ 342

Example 50 2-[3-(4-chlorophenyl)propyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide Compound I-131

Step 1: 1-(3-bromopropyl)-4-chlorobenzene

To a solution of 3-(4-chlorophenyl)propan-1-ol (0.25 g, 1.46 mmol) in dichloromethane (5.5 mL) cooled at 0° C. was added triphenylphosphine (0.42 g, 1.6 mmol) and carbon tetrabromide (0.51 g, 1.5 mmol) and the reaction was stirred at rt overnight. The reaction was quenched with water and extracted with DCM (2×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was purified by flash silica gel chromatography (0% to 70% EtOAc/hexanes) to afford 1-(3-bromopropyl)-4-chlorobenzene (0.34 g, quant.). LC-MS: (FA) ES+234.

Step 2: methyl 2-[3-(4-chlorophenyl)propyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxylate

The title compound was prepared from 1-(3-bromopropyl)-4-chlorobenzene (0.35 g, 1.48 mmol) and methyl 1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.20 g, 0.98 mmol) following the procedure outlined in Example 3, step 1 (0.16 g, 44%). LC-MS: (FA) ES+356.

Step 3: 2-[3-(4-chlorophenyl)propyl]-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-131

The title compound was prepared from methyl 2-[3-(4-chlorophenyl)propyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.15 g, 0.42 mmol) following the procedure outlined in Example 2 (0.1 g, 67%). LC-MS: (FA) ES+357; ¹H NMR (400 MHz, DMSO) δ 11.41 (s, 1H), 9.11 (s, 1H), 8.02 (dd, J=8.3, 1.8 Hz, 1H), 7.70 (d, J=8.3 Hz, 1H), 7.56 (d, J=7.3 Hz, 1H), 7.35-7.19 (m, 5H), 6.67 (d, J=7.3 Hz, 1H), 4.00 (t, J=7.2 Hz, 2H), 2.66-2.59 (m, 2H), 2.03-1.93 (m, 2H).

Example 51

The following compounds were prepared in a fashion analogous to that described in Example 50.

Compound LC-MS (FA) I-118 ES+ 324 I-140 ES+ 353 I-95 ES+ 362 I-96 ES+ 391 I-141 ES+ 351 I-82 ES+ 361 I-266 ES+ 410 I-137 ES+ 411

Example 52 N-hydroxy-3-isopropyl-4-oxo-2-phenyl-3,4-dihydroquinazoline-7-carboxamide; Compound I-9

Step 1: methyl 4-[(isopropylamino)carbonyl]-3-nitrobenzoate

To a solution of 4-(methoxycarbonyl)-2-nitrobenzoic acid (0.50 g, 2.22 mmol) in dichloromethane (20 mL) was added N,N-diisopropylethylamine (1.16 mL, 6.66 mmol) and 2-(7-aza-1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (0.89 g, 2.33 mmol). The reaction mixture was stirred for 15 min. Propan-2-amine (0.20 mL, 2.33 mmol) was added and the reaction mixture was stirred at rt overnight. The reaction mixture was then concentrated and the crude residue was purified by flash silica gel chromatography (30% to 60% EtOAc/hexanes) to afford methyl 4-[(isopropylamino)carbonyl]-3-nitrobenzoate (0.48 g, 80%). LC-MS: (FA) ES+268.

Step 2: methyl 3-amino-4-[(isopropylamino)carbonyl]benzoate

To a solution of methyl 4-[(isopropylamino)carbonyl]-3-nitrobenzoate (0.48 g, 1.78 mmol) in methanol (10 mL) and tetrahydrofuran (10 mL) was added 10% palladium on carbon (0.19 g, 0.18 mmol). The mixture was purged with H₂ gas (3×) and stirred under an atmosphere of H₂ for 1 d. The reaction mixture was then filtered through Celite, washed with MeOH and concentrated to afford methyl 3-amino-4-[(isopropylamino)carbonyl]benzoate (0.42 g, quant.). LC-MS: (FA) ES+237.

Step 3: methyl 3-isopropyl-4-oxo-2-phenyl-3,4-dihydroquinazoline-7-carboxylate

To a solution of methyl 3-amino-4-[(isopropylamino)carbonyl]benzoate (15 mg, 0.07 mmol) in ethanol (1.5 mL) was added acetic acid (32 μL, 0.56 mmol) and benzaldehyde (19.4 μL, 0.19 mmol). The reaction mixture was heated to 110° C. and stirred overnight. The mixture was then concentrated to dryness and taken up in chloroform (1 mL). To this solution was added manganese (IV) oxide (28 mg, 0.32 mmol) and the reaction mixture was heated to 110° C. and stirred for 2 d. The reaction mixture was then filtered through Celite, rinsed with chloroform and concentrated to dryness to afford methyl 3-isopropyl-4-oxo-2-phenyl-3,4-dihydroquinazoline-7-carboxylate. LC-MS: (FA) ES+323.

Step 4: N-hydroxy-3-isopropyl-4-oxo-2-phenyl-3,4-dihydroquinazoline-7-carboxamide Compound I-9

The title compound was prepared from methyl 3-isopropyl-4-oxo-2-phenyl-3,4-dihydroquinazoline-7-carboxylate following the procedure outlined in Example 2 (3.4 mg, 17%). LC-MS: (FA) ES+324; ¹H NMR (400 MHz, DMSO) δ 11.50 (s, 1H), 9.24 (s, 1H), 8.22 (d, J=8.3 Hz, 1H), 7.96 (s, 1H), 7.87 (dd, J=8.3, 1.6 Hz, 1H), 7.64-7.54 (m, 5H), 4.27-4.15 (m, 1H), 1.50 (d, J=6.8 Hz, 6H).

Example 53

The following compounds were prepared in a fashion analogous to that described in Example 52.

Compound LC-MS (FA) I-73 ES+ 440 I-263 ES+ 387 I-6 ES+ 393 I-150 ES+ 446 I-81 ES+ 420 I-53 ES+ 460 I-138 ES+ 458 I-133 ES+ 441 I-100 ES+ 420 I-106 ES+ 432 I-85 ES+ 490 I-26 ES+ 491 I-13 ES+ 458 I-274 ES+ 483 I-35 ES+ 468 I-166 ES+ 493 I-134 ES+ 474 I-237 ES+ 532 I-39 ES+ 468

Example 54 N-hydroxy-2-{2-[(4-methoxyphenyl)amino]ethyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-97

Step 1: methyl 2-(1,3-dioxolan-2-ylmethyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate

To a solution of methyl 1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.5 g, 1.72 mmol) in DMF (10 mL) was added potassium carbonate (1.2 g, 8.6 mmol) and 2-(bromomethyl)-1,3-dioxolane (0.62 mL, 6.03 mmol). The reaction mixture was heated at 140° C. and stirred for 5 h. The mixture was cooled to rt, water was added and the mixture was extracted with EtOAc (2×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was purified by flash silica gel chromatography (0% to 50% EtOAc/hexanes) to afford methyl 2-(1,3-dioxolan-2-ylmethyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.32 g, 64%). LC-MS: (FA) ES+290.

Step 2: methyl 1-oxo-2-(2-oxoethyl)-1,2-dihydroisoquinoline-7-carboxylate; Intermediate-16

To a solution of methyl 2-(1,3-dioxolan-2-ylmethyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.23 g, 0.8 mmol) in tetrahydrofuran (5 mL) was added 1.0 M hydrochloric acid in water (9.0 mL). The reaction mixture was heated to 65° C. and stirred overnight. The mixture was cooled to rt, water was added and the mixture was extracted with DCM (2×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was purified by flash silica gel chromatography (30% to 100% EtOAc/hexanes) to afford methyl 1-oxo-2-(2-oxoethyl)-1,2-dihydroisoquinoline-7-carboxylate (0.11 g, 56%). LC-MS: (FA) ES+246.

Step 3: methyl 2-{2-[(4-methoxyphenyl)amino]ethyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate

A solution of methyl 1-oxo-2-(2-oxoethyl)-1,2-dihydroisoquinoline-7-carboxylate (0.10 g, 0.41 mmol) and 4-methoxyaniline (65 mg, 0.53 mmol) in methanol (2 mL) was stirred at rt for 30 mins. Then acetic acid (2.3 μL, 0.04 mmol) and sodium cyanoborohydride (64 mg, 1.0 mmol) was added and the reaction mixture was stirred at rt overnight. The mixture was diluted with water and extracted with DCM (2×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was purified by flash silica gel chromatography (20% to 70% EtOAc/hexanes) to afford methyl 2-{2-[(4-methoxyphenyl)amino]ethyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.12 g, 83%). LC-MS: (FA) ES+353.

Step 4: N-hydroxy-2-{2-[(4-methoxyphenyl)amino]ethyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-97

The title compound was prepared from methyl 2-{2-[(4-methoxyphenyl)amino]ethyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (60 mg, 0.17 mmol) following the procedure outlined in Example 2 (17 mg, 28%). LC-MS: (FA) ES+354; ¹H NMR (300 MHz, DMSO) δ 11.34 (s, 1H), 9.10 (s, 1H), 8.67 (d, J=1.5 Hz, 1H), 8.03 (dd, J=8.3, 1.8 Hz, 1H), 7.70 (d, J=8.4 Hz, 1H), 7.47 (d, J=7.3 Hz, 1H), 6.75-6.56 (m, 5H), 5.40 (s, 1H), 4.11 (t, J=6.3 Hz, 2H), 3.63 (s, 3H), 3.39-3.28 (m, 2H).

Example 55

The following compounds were prepared in a fashion analogous to that described in Example 54 starting from Intermediate-16 and the corresponding amine.

Compound LC-MS (FA) I-113 ES+ 358 I-108 ES+ 390 I-77 ES+ 406

Example 56 2-{2-[(4-chlorobenzyl)(4-methoxyphenyl)amino]ethyl}-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-229

Step 1: methyl 2-{2-[(4-chlorobenzyl)(4-methoxyphenyl)amino]ethyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate

The title compound was prepared from methyl 2-{2-[(4-methoxyphenyl)amino]ethyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (60 mg, 0.17 mmol) and 4-chlorobenzaldehyde (34 mg, 0.24 mmol) following the procedure outlined in Example 54, step 3 (50 mg, 62%). LC-MS: (FA) ES+477.

Step 2: 2-{2-[(4-chlorobenzyl)(4-methoxyphenyl)amino]ethyl}-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-229

The title compound was prepared from methyl 2-{2-[(4-chlorobenzyl)(4-methoxyphenyl)amino]ethyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate following the procedure outlined in Example 2 (20 mg, 40%). LC-MS: (FA) ES+478; ¹H NMR (300 MHz, DMSO) δ 8.66 (s, 1H), 8.04 (dd, J=8.3, 1.7 Hz, 1H), 7.70 (d, J=8.3 Hz, 1H), 7.51 (d, J=7.3 Hz, 1H), 7.28 (d, J=8.4 Hz, 2H), 7.18 (d, J=8.4 Hz, 2H), 6.80-6.71 (m, 4H), 6.64 (d, J=7.3 Hz, 1H), 4.49 (s, 2H), 4.17 (t, J=6.6 Hz, 2H), 3.69-3.61 (m, 2H), 3.63 (s, 3H).

Example 57

The following compound was prepared in a fashion analogous to that described in Example 56.

Compound LC-MS (FA) I-253 ES+ 564

Example 58 N-hydroxy-2-(2-hydroxyethyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-158

Step 1: methyl 2-(2-hydroxyethyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate

To a solution of methyl 1-oxo-1,2-dihydroisoquinoline-7-carboxylate (1.26 g, 6.2 mmol) dissolved in acetonitrile (100 mL) was added 1,2-dibromoethane (5.3 mL, 62 mmol) and cesium carbonate (8.1 g, 24.8 mmol). The reaction mixture was stirred at rt for 1 d. The mixture was then concentrated, diluted with water and extracted with EtOAc (2×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was purified by flash silica gel chromatography (50% to 100% EtOAc/hexanes) to afford methyl 2-(2-hydroxyethyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (1.0 g, 65%). LC-MS: (FA) ES+248.

Step 2: N-hydroxy-2-(2-hydroxyethyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxamide Compound I-158

The title compound was prepared from methyl 2-(2-hydroxyethyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (42 mg, 0.17 mmol) following the procedure outlined in Example 2 (16 mg, 39%). LC-MS: (FA) ES+249; ¹H NMR (400 MHz, MeOD) δ 8.71 (d, J=1.7 Hz, 1H), 8.05 (dd, J=8.3, 1.9 Hz, 1H), 7.73 (d, J=8.3 Hz, 1H), 7.47 (d, J=7.3 Hz, 1H), 6.71 (d, J=7.3 Hz, 1H), 4.17 (t, J=5.4 Hz, 2H), 3.88 (t, J=5.3 Hz, 2H).

Example 59 N-hydroxy-1-oxo-2-(2-piperidin-1-ylethyl)-1,2-dihydroisoquinoline-7-carboxamide; Compound I-277

Step 1: methyl 1-oxo-2-(2-piperidin-1-ylethyl)-1,2-dihydroisoquinoline-7-carboxylate

The title compound was prepared from methyl 2-(2-bromoethyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (96 mg, 0.31 mmol) and piperidine (0.31 mL, 3.1 mmol) following the procedure outlined in Example 44, step 2 (80 mg, 82%). LC-MS: (FA) ES+315.

Step 2: N-hydroxy-1-oxo-2-(2-piperidin-1-ylethyl)-1,2-dihydroisoquinoline-7-carboxamide Compound I-277

The title compound was prepared from methyl 1-oxo-2-(2-piperidin-1-ylethyl)-1,2-dihydroisoquinoline-7-carboxylate following the procedure outlined in Example 2 (40 mg, 50%). LC-MS: (FA) ES+316; ¹H NMR (400 MHz, DMSO) δ 11.42 (s, 1H), 8.62 (d, J=1.7 Hz, 1H), 8.01 (dd, J=8.3, 1.8 Hz, 1H), 7.70 (d, J=8.3 Hz, 1H), 7.52 (d, J=7.3 Hz, 1H), 6.64 (d, J=7.3 Hz, 1H), 4.07 (t, J=6.5 Hz, 2H), 2.59-2.53 (m, 2H), 2.39 (s, 4H), 1.50-1.32 (m, 6H).

Example 60

The following compounds were prepared in a fashion analogous to that described in Example 59.

Compound LC-MS (FA) I-41 ES+ 317 I-294 ES+ 291 I-332 ES+ 405

Example 61 2-{3-[(diethylamino)methyl]benzyl}-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-208

Step 1: methyl 2-[3-(bromomethyl)benzyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxylate

To a solution of methyl 1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.15 g, 0.74 mmol) in DMF (7.5 mL) was added cesium carbonate (0.72 g, 2.2 mmol) and 1,3-bis(bromomethyl)benzene (0.29 g, 1.1 mmol). The reaction mixture was stirred at rt overnight. The mixture was diluted with water and extracted with EtOAc (2×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was purified by flash silica gel chromatography (0% to 5% EtOAc/DCM) to afford methyl 2-[3-(bromomethyl)benzyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.12 g, 42%). LC-MS: (FA) ES+388.

Step 2: methyl 2-{3-[(diethylamino)methyl]benzyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate

To a solution of methyl 2-[3-(bromomethyl)benzyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.10 g, 0.26 mmol) in tetrahydrofuran (7 mL) was added cesium carbonate (0.25 g, 0.78 mmol) and diethylamine (40 μL, 0.39 mmol). The reaction mixture was stirred at rt overnight. The mixture was diluted with water and extracted with EtOAc (2×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was purified by flash silica gel chromatography (0% to 5% MeOH/DCM) to afford methyl 2-{3-[(diethylamino)methyl]benzyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (71 mg, 72%). LC-MS: (FA) ES+379.

Step 3: 2-{3-[(diethylamino)methyl]benzyl}-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-208

The title compound was prepared from methyl 2-{3-[(diethylamino)methyl]benzyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate following the procedure outlined in Example 2 (61 mg, 86%).

LC-MS: (FA) ES+380; ¹H NMR (400 MHz, MeOD) δ 8.72 (s, 1H), 8.04 (dd, J=8.3, 1.7 Hz, 1H), 7.73 (d, J=8.3 Hz, 1H), 7.58 (d, J=7.3 Hz, 1H), 7.51-7.40 (m, 4H), 6.77 (d, J=7.3 Hz, 1H), 5.30 (s, 2H), 4.26 (s, 2H), 3.12 (q, J=7.3 Hz, 4H), 1.28 (t, J=7.3 Hz, 6H).

Example 62 tert-butyl {3-[7-[(hydroxyamino)carbonyl]-1-oxoisoquinolin-2(1H)-yl]propyl}(4-methoxyphenyl)carbamate; Compound I-188

Step 1: ethyl 2-{3-[(tert-butoxycarbonyl)(4-methoxyphenyl)amino]propyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate; Intermediate-17

To a solution of methyl 2-(3-bromopropyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.19 g, 0.60 mmol) dissolved in DMF (10 mL) was added tert-butyl (4-methoxyphenyl)carbamate (0.20 g, 0.89 mmol), tetra-n-butylammonium iodide (0.44 g, 1.19 mmol) and cesium carbonate (0.39 g, 1.19 mmol). The reaction mixture was stirred at rt for 6 h. The mixture was diluted with water and extracted with EtOAc (2×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was purified by flash silica gel chromatography (0% to 60% EtOAc/hexanes) to afford methyl 2-{3-[(tert-butoxycarbonyl)(4-methoxyphenyl)amino]propyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.11 g, 38%). LC-MS: (FA) ES+467.

Step 2: tert-butyl {3-[7-[(hydroxyamino)carbonyl]-1-oxoisoquinolin-2(1H)-yl]propyl}(4-methoxyphenyl)carbamate; Compound I-188

The title compound was prepared from methyl 2-{3-[(tert-butoxycarbonyl)(4-methoxyphenyl)amino]propyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (43 mg, 0.09 mmol) following the procedure outlined in Example 2 (23 mg, 53%). LC-MS: (FA) ES+468; ¹H NMR (400 MHz, DMSO) δ 8.62 (d, J=1.7 Hz, 1H), 8.02 (dd, J=8.3, 1.9 Hz, 1H), 7.70 (d, J=8.3 Hz, 1H), 7.54 (d, J=7.3 Hz, 1H), 7.17 (d, J=8.9 Hz, 2H), 6.89 (d, J=8.9 Hz, 2H), 6.66 (d, J=7.4 Hz, 1H), 3.97 (t, J=7.1 Hz, 2H), 3.74 (s, 3H), 3.58 (t, J=7.1 Hz, 2H), 1.87-1.78 (m, 2H), 1.30 (s, 9H).

Example 63

The following compound was prepared in a fashion analogous to that described in Example 62.

Compound LC-MS (FA) I-89 ES+ 439

Example 64 N-hydroxy-2-{3-[(4-methoxyphenyl)amino]propyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-34

Step 1: methyl 2-{3-[(4-methoxyphenyl)amino]propyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate

To a solution of methyl 2-{3-[(tert-butoxycarbonyl)(4-methoxyphenyl)amino]propyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (71 mg, 0.15 mmol) in methylene chloride (2 mL) was added 4.0 M hydrochloric acid in 1,4-dioxane (2.0 mL, 8.0 mmol). The reaction mixture was stirred at rt for 1 d. The mixture was then concentrated to dryness to afford methyl 2-{3-[(4-methoxyphenyl)amino]propyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (56 mg, quant.). LC-MS: (FA) ES+367.

Step 2: N-hydroxy-2-{3-[(4-methoxyphenyl)amino]propyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-34

The title compound was prepared from methyl 2-{3-[(4-methoxyphenyl)amino]propyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate following the procedure outlined in Example 2 (16 mg, 28%). LC-MS: (FA) ES+368; ¹H NMR (400 MHz, DMSO) δ 8.60 (d, J=1.7 Hz, 1H), 8.02 (dd, J=8.3, 1.8 Hz, 1H), 7.71 (d, J=8.3 Hz, 1H), 7.52 (d, J=9.0 Hz, 2H), 7.51 (d, J=7.3 Hz, 1H), 7.06 (d, J=9.0 Hz, 2H), 6.66 (d, J=7.4 Hz, 1H), 4.08 (t, J=7.2 Hz, 2H), 3.93 (t, J=7.2 Hz, 2H), 3.80 (s, 3H), 1.90-1.80 (m, 2H).

Example 65 N-hydroxy-3-(3-morpholinobenzyl)-4-oxo-3,4-dihydroquinazoline-6-carboxamide; Compound I-114

Step 1: ethyl 4-oxo-3,4-dihydroquinazoline-6-carboxylate; Intermediate-18

The title compound was prepared from 6-bromoquinazolin-4(3H)-one (6.0 g, 30 mmol) in a fashion analogous to that described in Example 1 (5.37 g, 92%). LC-MS: (FA) ES+219; ¹H NMR (400 MHz, CDCl₃) δ 10.88 (s, 1H), 8.99 (d, J=2.0 Hz, 1H), 8.44 (dd, J=8.5, 2.0 Hz, 1H), 8.17 (s, 1H), 7.82 (d, J=8.5 Hz, 1H), 4.44 (q, J=7.1 Hz, 2H), 1.44 (t, J=7.1 Hz, 3H).

Step 2: ethyl 3-(3-bromobenzyl)-4-oxo-3,4-dihydroquinazoline-6-carboxylate; Intermediate-19

Into a round-bottom flask was added ethyl 4-oxo-3,4-dihydroquinazoline-6-carboxylate (0.14 g, 0.63 mmol), 3-bromobenzyl bromide (0.24 g, 0.95 mmol), cesium carbonate (0.25 g, 0.76 mmol), acetonitrile (12 mL) and DMF (3 mL). The reaction mixture was stirred at rt for 16 h. The mixture was then concentrated and to the residue was added EtOAc and water. After separation, the aqueous phase was extracted with EtOAc (2×). The combined organic phases were then washed with brine, dried over anhydrous Na₂SO₄, filtered and concentrated. Flash column chromatography (25% to 50% EtOAc/hexanes) afforded ethyl 3-(3-bromobenzyl)-4-oxo-3,4-dihydroquinazoline-6-carboxylate (0.17 g, 68%) as a white solid. LC-MS: (FA) ES+388; ¹H NMR (CDCl₃, 300 MHz) δ 9.00 (d, J=1.70 Hz, 1H), 8.39 (dd, J=8.5, 1.9 Hz, 1H), 8.26 (s, 1H), 7.76 (d, J=8.5 Hz, 1H), 7.52 (s, 1H), 7.46 (d, J=7.7 Hz, 1H), 7.26 (m, 2H), 5.17 (s, 2H), 4.42 (q, J=7.2 Hz, 2H), 1.42 (t, J=7.0 Hz, 3H).

Step 3: ethyl 3-(3-morpholinobenzyl)-4-oxo-3,4-dihydroquinazoline-6-carboxylate

To a microwave vial was added ethyl 3-(3-bromobenzyl)-4-oxo-3,4-dihydroquinazoline-6-carboxylate (0.06 g, 0.16 mmol) and morpholine (0.040 mL, 0.47 mmol) in anhydrous 1,4-dioxane (3 mL). The solution was degassed under nitrogen for 10 min then cesium carbonate (0.15 g, 0.46 mmol) and 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (0.027 g, 0.047 mmol) were added followed by tris(dibenzylideneacetone)dipalladium(0) (0.021 g, 0.023 mmol). The reaction mixture was heated at 120° C. for 30 min in a microwave. The mixture was then concentrated and to the residue was added dichloromethane (3 mL) and water (1 mL). After separation, the aqueous layer was extracted with dichloromethane (3 mL). The combined organic layers were then washed with brine, dried over anhydrous Na₂SO₄, filtered and concentrated to give ethyl 3-(3-morpholinobenzyl)-4-oxo-3,4-dihydroquinazoline-6-carboxylate. LC-MS: (FA) ES+394.

Step 4: N-hydroxy-3-(3-morpholinobenzyl)-4-oxo-3,4-dihydroquinazoline-6-carboxamide; Compound I-114

The title compound was prepared from ethyl 3-(3-morpholinobenzyl)-4-oxo-3,4-dihydroquinazoline-6-carboxylate following the procedure outlined in Example 2 (19 mg, 32%). LC-MS: (FA) ES+381; ¹H NMR (CD₃OD, 400 MHz) δ 8.63 (d, J=1.8 Hz, 1H), 8.16 (dd, J=8.5, 2.0 Hz, 1H), 7.76 (d, J=8.5 Hz, 1H), 7.45 (m, 1H), 7.23 (t, J=7.8 Hz, 1H), 7.02 (t, J=1.7 Hz, 1H), 6.91 (m, 1H), 6.85 (d, J=7.5 Hz, 1H), 5.21 (s, 2H), 3.80 (t, J=4.8 Hz, 4H), 3.12 (t, J=4.8 Hz, 4H).

Example 66

The following compounds were prepared in a fashion analogous to that described in Example 65.

Compound LC-MS (FA) I-125 ES+ 395 I-142 ES+ 436 I-135 ES+ 374

Example 67 N-hydroxy-4-oxo-3-(3-(pyridin-4-yl)benzyl)-3,4-dihydroquinazoline-6-carboxamide; Compound I-128

Step 1: ethyl 4-oxo-3-(3-(pyridin-4-yl)benzyl)-3,4-dihydroquinazoline-6-carboxylate

To a microwave vial was added ethyl 3-(3-bromobenzyl)-4-oxo-3,4-dihydroquinazoline-6-carboxylate (0.050 g, 0.13 mmol), pyridine-4-boronic acid (0.032 g, 0.26 mmol) in a solution of 1,4-dioxane (2 mL) and water (0.4 mL). Sodium carbonate (0.041 g, 0.39 mmol) was added followed by [1,1′-bis(diphenylphosphino)ferrocene]palladium(II)dichloride (0.013 g, 0.015 mmol). The reaction mixture was heated at 90° C. for 16 h. The mixture was then concentrated and to the residue was added dichloromethane (3 mL) and water (1 mL). After separation, the aqueous phase was extracted with dichloromethane (3 mL). The combined organic layers were then washed with brine, dried over anhydrous Na₂SO₄, filtered and concentrated to afford ethyl 4-oxo-3-(3-(pyridin-4-yl)benzyl)-3,4-dihydroquinazoline-6-carboxylate. LC-MS: (FA) ES+386.

Step 2: N-hydroxy-4-oxo-3-(3-(pyridin-4-yl)benzyl)-3,4-dihydroquinazoline-6-carboxamide; Compound I-128

The title compound was prepared from ethyl 4-oxo-3-(3-(pyridin-4-yl)benzyl)-3,4-dihydroquinazoline-6-carboxylate following the procedure outlined in Example 2 (20 mg, 42%). LC-MS: (FA) ES+373; ¹H NMR (DMSO-d₆, 400 MHz) δ 11.47 (s, 1H), 9.15 (s, 1H), 8.73 (s, 1H), 8.63 (m, 2H), 8.55 (d, J=2.0 Hz, 1H), 8.15 (dd, J=8.5, 2.0 Hz, 1H), 7.88 (m, 1H), 7.74 (m, 2H), 7.68 (m, 2H), 7.48 (m, 2H), 5.29 (s, 2H).

Example 68

The following compounds were prepared in a fashion analogous to that described in Example 67.

Compound LC-MS (FA) I-220 ES+ 387 I-124 ES+ 440 I-60 ES+ 429 I-23 ES+ 441 I-268 ES+ 428 I-281 ES+ 402 I-177 ES+ 387 I-69 ES+ 440 I-181 ES+ 390 I-182 ES+ 414 I-126 ES+ 455 I-143 ES+ 403 I-32 ES+ 414 I-37 ES+ 456 I-46 ES+ 440 I-28 ES+ 407 I-80 ES+ 429 I-79 ES+ 508 I-254 ES+ 520 I-230 ES+ 473 I-244 ES+ 480 I-136 ES+ 403 I-299 ES+ 534 I-334 ES+ 443 I-341 ES+ 465 I-302 ES+ 443 I-327 ES+ 487 I-295 ES+ 454 I-331 ES+ 387 I-316 ES+ 421 I-347 ES+ 422 I-321 ES+ 430 I-314 ES+ 421 I-313 ES+ 455 I-322 ES+ 401 I-329 ES+ 417 I-339 ES+ 416 I-318 ES+ 443 I-312 ES+ 470 I-304 ES+ 400 I-291 ES+ 470 I-300 ES+ 404 I-320 ES+ 417 I-297 ES+ 429 I-296 ES+ 400 I-309 ES+ 494 I-311 ES+ 454 I-301 ES+ 400 I-303 ES+ 416 I-323 ES+ 376 I-345 ES+ 455 I-325 ES+ 454 I-342 ES+ 429 I-336 ES+ 405

Example 69 2-(3-aminopropyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide.CH₂O₂; Compound I-173

Step 1: methyl 2-{3-[(tert-butoxycarbonyl)amino]propyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate Intermediate-20

To a stirred suspension of sodium hydride (60% in mineral oil, 0.30 g, 7.4 mmol) in DMF (10 mL) under an atmosphere of nitrogen was added methyl 1-oxo-1,2-dihydroisoquinoline-7-carboxylate (1.0 g, 4.9 mmol) in DMF (10 mL) dropwise. The mixture was stirred for 30 mins, then tert-butyl (3-bromopropyl)carbamate (1.76 g, 7.4 mmol) dissolved in DMF (5 mL) was added dropwise via cannula and the resulting solution was stirred at rt overnight. The reaction was quenched with water and extracted with EtOAc (2×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was purified by flash silica gel chromatography (20% to 90% EtOAc/hexanes) to afford methyl 2-{3-[(tert-butoxycarbonyl)amino]propyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.99 g, 56%). LC-MS: (FA) ES+361.

Step 2: methyl 2-(3-aminopropyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate.HCl; Intermediate-21

To a solution of methyl 2-{3-[(tert-butoxycarbonyl)amino]propyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.90 g, 2.5 mmol) in methylene chloride (20 mL) was added 4.0 M hydrochloric acid in 1,4-dioxane (10.0 mL, 40 mmol). The reaction mixture was stirred at rt for 5 h. The reaction mixture was concentrated to dryness to afford methyl 2-(3-aminopropyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate.HCl (0.74 g, quant.). LC-MS: (FA) ES+261.

Step 3: 2-(3-aminopropyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide.CH₂O₂; Compound I-173

The title compound was prepared from methyl 2-(3-aminopropyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate.HCl (84 mg, 0.28 mmol) following the procedure outlined in Example 2 (53 mg, 61%). The title compound was purified using HPLC conditions that included formic acid and resulted in the isolated of the formic acid salt. LC-MS: (FA) ES+262; ¹H NMR (400 MHz, DMSO) δ 8.64 (d, J=1.4 Hz, 1H), 8.39 (s, 1H), 8.04 (dd, J=8.3, 1.7 Hz, 1H), 7.72 (d, J=8.3 Hz, 1H), 7.59 (d, J=7.2 Hz, 1H), 6.71 (d, J=7.1 Hz, 1H), 4.05 (t, J=6.3 Hz, 2H), 2.75 (t, J=6.7 Hz, 2H), 1.99-1.89 (m, 2H).

Example 70

The following compound was prepared in a fashion analogous to that described in Example 69.

Compound LC-MS (FA) I-207 ES+ 248

Example 71 2-{3-[(2,2-dimethylpropanoyl)amino]propyl}-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-8

Step 1: methyl 2-{3-[(2,2-dimethylpropanoyl)amino]propyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate

To a solution of methyl 2-(3-aminopropyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate.HCl (0.13 g, 0.44 mmol) dissolved in methylene chloride (8 mL) was added triethylamine (0.18 mL, 1.3 mmol) and 2,2-dimethylpropanoyl chloride (0.08 mL, 0.66 mmol). The reaction mixture was stirred at rt for 2 h. The mixture was then concentrated to dryness and the residue was purified by flash silica gel chromatography (40% to 90% EtOAc/hexanes) to afford methyl 2-{3-[(2,2-dimethylpropanoyl)amino]propyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.14 g, 92%). LC-MS: (FA) ES+345.

Step 2: 2-{3-[(2,2-dimethylpropanoyl)amino]propyl}-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-8

The title compound was prepared from methyl 2-{3-[(2,2-dimethylpropanoyl)amino]propyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.13 g, 0.38 mmol) following the procedure outlined in Example 2 (0.10 g, 78%). LC-MS: (FA) ES+346; ¹H NMR (400 MHz, DMSO) δ 11.43 (s, 1H), 9.17 (s, 1H), 8.64 (d, J=1.6 Hz, 1H), 8.03 (dd, J=8.3, 1.8 Hz, 1H), 7.72 (d, J=8.3 Hz, 1H), 7.58 (d, J=7.3 Hz, 1H), 7.52 (t, J=5.6 Hz, 1H), 6.68 (d, J=7.3 Hz, 1H), 3.96 (t, J=6.9 Hz, 2H), 3.08 (dd, J=12.8, 6.6 Hz, 2H), 1.85-1.76 (m, 2H), 1.09 (s, 9H).

Example 72 N-hydroxy-2-[3-(isobutyrylamino)benzyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-174

Step 1: tert-butyl [3-(hydroxymethyl)phenyl]carbamate

To a solution of (3-aminophenyl)methanol (0.50 g, 4.06 mmol) dissolved in tetrahydrofuran (15 mL) was added di-tert-butyl dicarbonate (0.97 g, 4.5 mmol). The reaction mixture was stirred at rt overnight. The mixture was then concentrated to dryness and the residue was purified by flash silica gel chromatography (0% to 50% EtOAc/hexanes) to afford tert-butyl [3-(hydroxymethyl)phenyl]carbamate (0.90 g, 99%). LC-MS: (FA) ES+150.

Step 2: tert-butyl [3-(bromomethyl)phenyl]carbamate

To a solution of tert-butyl [3-(hydroxymethyl)phenyl]carbamate (0.90 g, 4.0 mmol) in dichloromethane (15 mL) cooled at 0° C. was added triphenylphosphine (1.59 g, 6.05 mmol) and carbon tetrabromide (2.01 g, 6.05 mmol) and the reaction was stirred at rt overnight. The reaction was quenched with water and extracted with DCM (2×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was purified by flash silica gel chromatography (0% to 20% EtOAc/hexanes) to afford tert-butyl [3-(bromomethyl)phenyl]carbamate (0.82 g, 70%). LC-MS: (FA) ES+271.

Step 3: methyl 2-{3-[(tert-butoxycarbonyl)amino]benzyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate

The title compound was prepared from tert-butyl [3-(bromomethyl)phenyl]carbamate (0.42 g, 1.48 mmol) and methyl 1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.20 g, 0.98 mmol) following the procedure outlined in Example 3, step 1 (0.31 g, 77%). LC-MS: (FA) ES+409.

Step 4: methyl 2-(3-aminobenzyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate.HCl; Intermediate-22

To a solution of methyl 2-{3-[(tert-butoxycarbonyl)amino]benzyl}-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.23 g, 0.57 mmol) in methylene chloride (5 mL) was added 4.0 M hydrochloric acid in 1,4-dioxane (7 mL, 28 mmol). The reaction mixture was stirred at rt for 2 h. The reaction mixture was concentrated to dryness to afford methyl 2-(3-aminobenzyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate.HCl (0.20 g, quant.). LC-MS: (FA) ES+309.

Step 5: methyl 2-[3-(isobutyrylamino)benzyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxylate

To a solution of methyl 2-(3-aminobenzyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate.HCl (0.15 g, 0.44 mmol) dissolved in methylene chloride (5 mL) was added triethylamine (0.30 mL, 2.2 mmol) and 2-methylpropanoyl chloride (0.09 mL, 0.87 mmol). The reaction mixture was stirred at rt for 2 h. The mixture was then concentrated to dryness and the residue was purified by flash silica gel chromatography (0% to 5% EtOAc/DCM) to afford methyl 2-[3-(isobutyrylamino)benzyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.15 g, 88%). LC-MS: (FA) ES+379.

Step 6: N-hydroxy-2-[3-(isobutyrylamino)benzyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-174

The title compound was prepared from methyl 2-[3-(isobutyrylamino)benzyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.15 g, 0.40 mmol) following the procedure outlined in Example 2 (0.12 g, 79%). LC-MS: (FA) ES+380; ¹H NMR (400 MHz, DMSO) δ 9.85 (s, 1H), 8.64 (d, J=1.7 Hz, 1H), 8.04 (dd, J=8.3, 1.8 Hz, 1H), 7.73 (d, J=8.3 Hz, 1H), 7.62 (d, J=7.4 Hz, 1H), 7.57 (d, J=8.1 Hz, 1H), 7.48 (s, 1H), 7.25 (t, J=7.9 Hz, 1H), 6.98 (d, J=7.7 Hz, 1H), 6.71 (d, J=7.4 Hz, 1H), 5.17 (s, 2H), 2.58-2.50 (m, 1H), 1.05 (d, J=6.8 Hz, 6H).

Example 73 tert-butyl 4-{[(3-{[7-[(hydroxyamino)carbonyl]-1-oxoisoquinolin-2(1H)-yl]methyl}phenyl)amino]carbonyl}-4-methylpiperidine-1-carboxylate; Compound I-93

Step 1: methyl 2-[3-({[1-(tert-butoxycarbonyl)-4-methylpiperidin-4-yl]carbonyl}amino)benzyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxylate

To a solution of methyl 2-(3-aminobenzyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate.HCl (0.22 g, 0.64 mmol) in pyridine (5 mL) was added 1-(tert-butoxycarbonyl)-4-methylpiperidine-4-carboxylic acid (0.17 g, 0.70 mmol) and N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (0.37 g, 1.9 mmol). The reaction mixture was stirred at rt overnight. The reaction mixture was then concentrated and the crude residue was purified by flash silica gel chromatography (0% to 5% EtOAc/DCM) to afford methyl 2-[3-({[1-(tert-butoxycarbonyl)-4-methylpiperidin-4-yl]carbonyl}amino)benzyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.29 g, 83%). LC-MS: (FA) ES+434.

Step 2: tert-butyl 4-{[(3-{[7-[(hydroxyamino)carbonyl]-1-oxoisoquinolin-2(1H)-yl]methyl}phenyl)amino]carbonyl}-4-methylpiperidine-1-carboxylate; Compound I-93

The title compound was prepared from methyl 2-[3-({[1-(tert-butoxycarbonyl)-4-methylpiperidin-4-yl]carbonyl}amino)benzyl]-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (0.24 g, 0.45 mmol) following the procedure outlined in Example 2 (0.15 g, 63%). LC-MS: (FA) ES+535; ¹H NMR (400 MHz, DMSO) δ 11.37 (s, 1H), 9.35 (s, 1H), 9.12 (s, 1H), 8.65 (d, J=1.7 Hz, 1H), 8.04 (dd, J=8.3, 1.9 Hz, 1H), 7.73 (d, J=8.3 Hz, 1H), 7.63 (d, J=8.3 Hz, 1H), 7.62-7.55 (m, 2H), 7.25 (t, J=7.8 Hz, 1H), 7.00 (d, J=7.7 Hz, 1H), 6.72 (d, J=7.3 Hz, 1H), 5.17 (s, 2H), 3.56-3.47 (m, 2H), 3.15-3.01 (m, 2H), 2.07-1.98 (m, 2H), 1.38 (s, 9H), 1.38-1.31 (m, 2H), 1.21 (s, 3H).

Example 74 [3-(1H-indazol-1-yl)phenyl]methanol; Intermediate-23

To a round bottom flask was added 1H-indazole (0.47 g, 4.0 mmol), (3-iodophenyl)methanol (1.4 g, 6.0 mmol), ferric chloride (0.13 g, 0.8 mmol), and tri-potassium phosphate monohydrate (1.84 g, 8.0 mmol). Degassed water (2 mL) was then added followed by (1R,2R)-N,N′-dimethylcyclohexane-1,2-diamine (0.25 mL, 1.6 mmol). The reaction mixture was then heated to 135° C. and stirred overnight. The mixture was cooled to rt, diluted with water and extracted with EtOAc (2×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was purified by flash silica gel chromatography (0% to 50% EtOAc/hexanes) to afford [3-(1H-indazol-1-yl)phenyl]methanol (0.67 g, 74%). LC-MS: (FA) ES+225.

Example 75 2-(2-{(cyclopropylcarbonyl)[3-(1H-pyrazol-1-yl)phenyl]amino}ethyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-45

Step 1: methyl 1-oxo-2-(2-{[3-(1H-pyrazol-1-yl)phenyl]amino}ethyl)-1,2-dihydroisoquinoline-7-carboxylate

A solution of methyl 1-oxo-2-(2-oxoethyl)-1,2-dihydroisoquinoline-7-carboxylate (0.15 g, 0.61 mmol) and 3-(1H-pyrazol-1-yl)aniline (0.15 g, 0.92 mmol) in methanol (2 mL) was stirred at rt for 30 mins. Then acetic acid (3.5 μL, 0.06 mmol) and sodium cyanoborohydride (96 mg, 1.5 mmol) was added and the reaction mixture was stirred at rt overnight. The mixture was diluted with water and extracted with DCM (2×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was purified by flash silica gel chromatography (20% to 70% EtOAc/hexanes) to afford methyl 1-oxo-2-(2-{[3-(1H-pyrazol-1-yl)phenyl]amino}ethyl)-1,2-dihydroisoquinoline-7-carboxylate (0.14 g, 59%). LC-MS: (FA) ES+389.

Step 2: methyl 2-(2-{(cyclopropylcarbonyl)[3-(1H-pyrazol-1-yl)phenyl]amino}ethyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate

To a solution of methyl 1-oxo-2-(2-{[3-(1H-pyrazol-1-yl)phenyl]amino}ethyl)-1,2-dihydroisoquinoline-7-carboxylate (77 mg, 0.20 mmol) dissolved in methylene chloride (1.5 mL) was added N,N-diisopropylethylamine (69 μL, 0.4 mmol) and cyclopropanecarbonyl chloride (27 μL, 0.30 mmol). The reaction mixture was stirred at rt for 1 h. The mixture was then concentrated to dryness and the residue was purified by flash silica gel chromatography (30% to 100% EtOAc/hexanes) to afford methyl 2-(2-{(cyclopropylcarbonyl)[3-(1H-pyrazol-1-yl)phenyl]amino}ethyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (77 mg, 85%). LC-MS: (FA) ES+457.

Step 3: 2-(2-{(cyclopropylcarbonyl)[3-(1H-pyrazol-1-yl)phenyl]amino}ethyl)-N-hydroxy-1-oxo-1,2-dihydroisoquinoline-7-carboxamide; Compound I-45

The title compound was prepared from methyl 2-(2-{(cyclopropylcarbonyl)[3-(1H-pyrazol-1-yl)phenyl]amino}ethyl)-1-oxo-1,2-dihydroisoquinoline-7-carboxylate (77 mg, 0.17 mmol) following the procedure outlined in Example 2 (50 mg, 65%). LC-MS: (FA) ES+458; ¹H NMR (400 MHz, MeOD) δ 8.56 (s, 1H), 8.01-7.97 (m, 2H), 7.64 (d, J=1.6 Hz, 1H), 7.62-7.55 (m, 2H), 7.54-7.51 (m, 1H), 7.42-7.36 (m, 2H), 7.20 (dd, J=7.9, 1.1 Hz, 1H), 6.67 (d, J=7.3 Hz, 1H), 6.47-6.44 (m, 1H), 4.34 (t, J=5.7 Hz, 2H), 4.25-4.19 (m, 2H), 1.43 (s, 1H), 0.95-0.89 (m, 2H), 0.73-0.67 (m, 2H).

Example 76 N-hydroxy-4-oxo-3-(2-phenylpropan-2-yl)-3,4-dihydroquinazoline-6-carboxamide; Compound I-413

Step 1: Methyl 4-nitro-3-[(2-phenylpropan-2-yl)carbamoyl]benzoate

A mixture of 5-(methoxycarbonyl)-2-nitrobenzoic acid (0.12 g, 0.53 mmol), DMF (2.50 mL), triethylamine (0.22 mL, 1.6 mmol) and fluoro-N,N,N′,N′-tetramethylformamidinium hexafluorophosphate (0.17 g, 0.64 mmol) was stirred for 30 min and cumylamine (0.092 mL, 0.64 mmol) was added. The reaction mixture was stirred at rt for 1 d. Water was added and the mixture was extracted with EtOAc (2×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was purified by flash silica gel chromatography (50% to 100% EtOAc/hexanes) to afford methyl 4-nitro-3-[(2-phenylpropan-2-yl)carbamoyl]benzoate (0.13 g, 70%). LC-MS: (FA) ES+343.

Step 2: Methyl 4-amino-3-[(2-phenylpropan-2-yl)carbamoyl]benzoate

To a solution of methyl 4-nitro-3-[(2-phenylpropan-2-yl)carbamoyl]benzoate (0.12 g, 0.35 mmol) in methanol (2.5 mL) and ethyl acetate (2.5 mL) was added 10% palladium on carbon (12 mg). The mixture was purged with H₂ gas (3×) and stirred under an atmosphere of H₂ for 5 h. The reaction mixture was then filtered through Celite, washed with MeOH and concentrated. The residue was purified by flash silica gel chromatography (50% to 100% EtOAc/hexanes) to afford methyl 4-amino-3-[(2-phenylpropan-2-yl)carbamoyl]benzoate (0.11 g, 99%). LC-MS: (FA) ES+313.

Step 3: Methyl 4-oxo-3-(2-phenylpropan-2-yl)-3,4-dihydroquinazoline-6-carboxylate

To a solution of methyl 4-amino-3-[(2-phenylpropan-2-yl)carbamoyl]benzoate (0.13 g, 0.42 mmol) in DMF (2.5 mL) was added ethyl orthoformate (3.0 mL, 18 mmol) followed by one scoop of 3 Å molecular sieves. The reaction mixture was heated to 150° C. and stirred for 1 d. The mixture was cooled to rt, water was added and the mixture was extracted with EtOAc (2×). The combined organic phases were then washed with water, and brine, dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was purified by flash silica gel chromatography (50% to 100% EtOAc/hexanes) to afford methyl 4-oxo-3-(2-phenylpropan-2-yl)-3,4-dihydroquinazoline-6-carboxylate (0.11 g, 84%). LC-MS: (FA) ES+323.

Step 4: N-hydroxy-4-oxo-3-(2-phenylpropan-2-yl)-3,4-dihydroquinazoline-6-carboxamide; Compound I-413

A mixture of hydroxylamine hydrochloride (2.0 g, 29 mmol) in methanol (10.0 mL) was heated at 90° C. under a dry nitrogen atmosphere until homogeneous. To this heated solution was added a solution of potassium hydroxide (2.85 g, 50.8 mmol) in methanol (6.0 mL). A precipitate formed on mixing. After heating at 90° C. for 30 minutes, the mixture was cooled to rt and the solids were allowed to settle. The resulting solution was assumed to contain 1.7 M hydroxylamine.potassium salt and was carefully removed by syringe to exclude solids. An aliquot of the above solution (2.0 mL, 3.5 mmol) was added to a solution of methyl 4-oxo-3-(2-phenylpropan-2-yl)-3,4-dihydroquinazoline-6-carboxylate (0.11 g, 0.35 mmol) in methanol (0.75 mL) and DMF (0.50 mL). After stirring for 4 h at rt, excess reagent was quenched by the addition of acetic acid (0.2 mL, 3.5 mmol). The mixture was concentrated to dryness and the residue was twice co-evaporated with toluene. The crude product was purified by preparative HPLC to afford N-hydroxy-4-oxo-3-(2-phenylpropan-2-yl)-3,4-dihydroquinazoline-6-carboxamide (84 mg, 75%). LC-MS: (FA) ES+324; ¹H NMR (400 MHz, DMSO) δ 11.25 (s, 1H), 9.11 (s, 1H), 8.72 (s, 1H), 8.36 (d, J=1.9 Hz, 1H), 8.14 (dd, J=8.5, 2.1 Hz, 1H), 7.76 (d, J=8.5 Hz, 1H), 7.34-7.14 (m, 5H), 1.96 (s, 6H).

Example 77

The following compounds were prepared in a fashion analogous to that described in Example 52.

Compound LC-MS (FA) I-395 ES+ 312 I-401 ES+ 282 I-416 ES+ 288 I-414 ES+ 316 I-417 ES+ 324 I-398 ES+ 283 I-410 ES+ 313 I-396 ES+ 359 I-412 ES+ 314 I-405 ES+ 332 I-420 ES+ 274 I-408 ES+ 310 I-404 ES+ 323 I-403 ES+ 300 I-409 ES+ 302 I-411 ES+ 314 I-415 ES+ 335 I-406 ES+ 310 I-402 ES+ 262 I-399 ES+ 300

Example 78 HDAC6 enzyme assay

To measure the inhibition of HDAC6 activity, purified human HDAC6 (BPS Bioscience; Cat. No. 5006) is incubated with substrate Ac-Arg-Gly-Lys(Ac)-AMC peptide (Bachem Biosciences; Cat. No. I-1925) for 1 hour at 30° C. in the presence of test compounds or vehicle DMSO control. The reaction is stopped with the HDAC inhibitor trichostatin A (Sigma; Cat. No. T8552) and the amount of Arg-Gly-Lys-AMC generated is quantitated by digestion with trypsin (Sigma; Cat. No. T1426) and subsequent measurement of the amount of AMC released using a fluorescent plate reader (Pherastar; BMG Technologies) set at Ex 340 nm and Em 460 nm. Concentration response curves are generated by calculating the fluorescence increase in test compound-treated samples relative to DMSO-treated controls, and percentage inhibition values at a single concentration or enzyme inhibition (IC₅₀) values are determined from those curves. One skilled in the art will appreciate that the values generated either as percentage inhibition at a single concentration or IC₅₀ values are subject to experimental variation.

Example 79 Nuclear Extract HDAC Assay

As a screen against Class I HDAC enzymes, HeLa nuclear extract (BIOMOL; Cat. No. KI-140) is incubated with Ac-Arg-Gly-Lys(Ac)-AMC peptide (Bachem Biosciences; Cat. No. 1-1925) in the presence of test compounds or vehicle DMSO control. The HeLa nuclear extract is enriched for Class I enzymes HDAC1, -2 and -3. The reaction is stopped with the HDAC inhibitor Trichostatin A (Sigma; Cat. No. T8552) and the amount of Arg-Gly-Lys-AMC generated is quantitated by digestion with trypsin (Sigma; Cat. No. T1426) and subsequent measurement of the amount of AMC released using a fluorescent plate reader (Pherastar; BMG Technologies) set at Ex 340 nm and Em 460 nm. Concentration response curves are generated by calculating the fluorescence increase in test compound-treated samples relative to DMSO-treated controls, and enzyme inhibition (IC₅₀) values are determined from those curves.

Example 80 Western Blot and Immunofluorescence Assays

Cellular potency and selectivity of compounds are determined using a published assay (Haggarty et al., Proc. Natl. Acad. Sci. USA 2003, 100 (8): 4389-4394) using Hela cells (ATCC cat# CCL-2™) which are maintained in MEM medium (Invitrogen) supplemented with 10% FBS; or multiple myeloma cells RPMI-8226 (ATCC cat# CCL-155™) which are maintained in RPMI 1640 medium (Invitrogen) supplemented with 10% FBS. Briefly, cells are treated with inhibitors for 6 or 24 h and either lysed for Western blotting, or fixed for immunofluorescence analyses. HDAC6 potency is determined by measuring K40 hyperacetylation of alpha-tubulin with an acetylation selective monoclonal antibody (Sigma cat# T7451) in IC50 experiments. Selectivity against Class I HDAC activity is determined similarly using an antibody that recognizes hyperacetylation of histone H4 (Upstate cat#06-866) in the Western blotting assay or nuclear acetylation (Abeam cat# ab21623) in the immunofluorescence assay.

Example 81 In Vivo Tumor Efficacy Model

Female NCr-Nude mice (age 6-8 weeks, Charles River Labs) are aseptically injected into the subcutaneous space in the right dorsal flank with 1.0-5.0×10⁶ cells (SKOV-3, HCT-116, BxPC3) in 100 μL of a 1:1 ratio of serum-free culture media (Sigma Aldrich) and BD Matrigel™ (BD Biosciences) using a 1 mL 26⅜ gauge needle (Becton Dickinson Ref#309625). Alternatively, some xenograft models require the use of more immunocompromised strains of mice such as CB-17 SCID (Charles River Labs) or NOD-SCID (Jackson Laboratory). Furthermore, some xenograft models require serial passaging of tumor fragments in which small fragments of tumor tissue (approximately 1 mm³) are implanted subcutaneously in the right dorsal flank of anesthetized (3-5% isoflourane/oxygen mixture) NCr-Nude, CB-17 SCID or NOD-SCID mice (age 5-8 weeks, Charles River Labs or Jackson Laboratory) via a 13-ga trocar needle (Popper & Sons 7927). Tumor volume is monitored twice weekly with Vernier calipers. The mean tumor volume is calculated using the formula V=W²×L/2. When the mean tumor volume is approximately 200 mm³, the animals are randomized into treatment groups of ten animals each. Drug treatment typically includes the test compound as a single agent, and may include combinations of the test compound and other anticancer agents. Dosing and schedules are determined for each experiment based on previous results obtained from pharmacokinetic/pharmacodynamic and maximum tolerated dose studies. The control group will receive vehicle without any drug. Typically, test compound (100-200 μL) is administered via intravenous (27-ga needle), oral (20-ga gavage needle) or subcutaneous (27-ga needle) routes at various doses and schedules. Tumor size and body weight are measured twice a week and the study is terminated when the control tumors reach approximately 2000 mm³, and/or if tumor volume exceeds 10% of the animal body weight or if the body weight loss exceeds 20%.

The differences in tumor growth trends over time between pairs of treatment groups are assessed using linear mixed effects regression models. These models account for the fact that each animal is measured at multiple time points. A separate model is fit for each comparison, and the areas under the curve (AUC) for each treatment group are calculated using the predicted values from the model. The percent decrease in AUC (dAUC) relative to the reference group is then calculated. A statistically significant P value suggests that the trends over time for the two treatment groups are different.

The tumor measurements observed on a date pre-specified by the researcher (typically the last day of treatment) are analyzed to assess tumor growth inhibition. For this analysis, a T/C ratio is calculated for each animal by dividing the tumor measurement for the given animal by the mean tumor measurement across all control animals. The T/C ratios across a treatment group are compared to the T/C ratios of the control group using a two-tailed Welch's t-test. To adjust for multiplicity, a False Discovery Rate (FDR) is calculated for each comparison using the approach described by Benjamini and Hochberg, J. R. Stat. Soc. B 1995, 57:289-300.

As detailed above, compounds of the invention inhibit HDAC6. In certain embodiments, compounds of the invention inhibit HDAC6 with the percent inhibition at a μM concentration as shown in the table below.

Percent Com- Concentration Percent Com- Concentration Inhi- pound (μM) Inhibition pound (μM) bition I-1 0.412 95.945 I-171 0.412 87.01 I-2 0.412 82.17 I-172 0.412 94.515 I-3 0.412 95.787 I-173 0.37 75.39 I-4 0.412 79.61 I-174 0.37 98.757 I-5 0.412 96.5 I-175 0.412 95.9 I-6 0.412 77.65 I-176 0.412 94.217 I-7 0.412 94.87 I-177 0.37 93.18 I-8 0.37 91.747 I-178 0.412 95.043 I-9 0.412 85 I-179 0.37 97.47 I-10 0.412 84.46 I-180 0.412 97.02 I-11 0.412 97.02 I-181 0.37 92.74 I-12 0.37 99.18 I-182 0.37 78.93 I-13 0.37 82.12 I-183 0.412 67.435 I-14 0.412 95.13 I-184 0.412 88.917 I-15 0.412 32.69 I-185 0.412 95.467 I-16 0.412 95.827 I-186 0.412 95.455 I-17 0.412 30.63 I-187 0.412 95.09 I-18 0.412 68.925 I-188 0.412 94.43 I-19 0.412 94.443 I-189 0.412 97.19 I-20 0.412 82.953 I-190 0.412 92.93 I-21 0.412 96.103 I-191 0.412 95.485 I-22 0.412 96.44 I-192 0.412 61.495 I-23 0.37 92.25 I-193 0.412 79.083 I-24 0.412 93.735 I-194 0.412 36.065 I-25 0.412 84.71 I-195 0.412 16.065 I-26 0.37 92.26 I-196 0.412 95.18 I-27 0.412 98.64 I-197 0.412 96.5 I-28 0.37 85.49 I-198 0.412 96.435 I-29 0.412 78.86 I-199 0.412 42.35 I-30 0.412 93.587 I-200 0.37 93.34 I-31 0.412 89.465 I-201 0.412 88.795 I-32 0.37 83.61 I-202 0.412 96.1 I-33 0.412 94.38 I-203 0.412 46.43 I-34 0.412 94.28 I-204 0.412 98.74 I-35 0.37 65.97 I-205 0.37 89.46 I-36 0.412 91.788 I-206 0.412 95.807 I-37 0.37 89.85 I-207 0.412 59.48 I-38 0.412 96.135 I-208 0.412 89.875 I-39 0.37 84.51 I-209 0.412 95.855 I-40 0.412 44.48 I-210 0.412 80.73 I-41 0.37 73.203 I-211 0.412 92.298 I-42 0.412 94.427 I-212 0.412 96.875 I-43 0.412 96.12 I-213 0.412 94.025 I-44 0.412 91.76 I-214 0.412 65.81 I-45 0.37 89.63 I-215 0.37 100.23 I-46 0.37 94.38 I-216 0.37 85.72 I-47 0.412 44.175 I-217 0.412 99.4 I-48 0.412 97.05 I-218 0.412 90.38 I-49 0.412 54.96 I-219 0.412 94.093 I-50 0.412 94.91 I-220 0.37 98.307 I-51 0.412 96.245 I-221 0.412 88.1 I-52 0.412 90.013 I-222 0.412 94.565 I-53 0.37 65.52 I-223 0.412 94.887 I-54 0.412 94.51 I-224 0.37 96.33 I-55 0.412 93.933 I-225 0.412 40.28 I-56 0.412 69 I-226 0.412 84.45 I-57 0.412 77.387 I-227 0.412 93.71 I-58 0.412 80.41 I-228 0.412 86.86 I-59 0.412 80.7 I-229 0.412 83.18 I-60 0.37 98.375 I-230 0.37 92.37 I-61 0.412 95.693 I-231 0.412 94.75 I-62 0.412 98.02 I-232 0.412 70.87 I-63 0.412 93.23 I-233 0.412 91.12 I-64 0.412 93.075 I-234 0.412 98.58 I-65 0.412 93 I-235 0.412 87.55 I-66 0.412 89.46 I-236 0.412 96.18 I-67 0.412 49.213 I-237 0.37 87.99 I-68 0.412 61.68 I-238 0.412 86.195 I-69 0.37 82.05 I-239 0.412 93.82 I-70 0.412 46.695 I-240 0.412 96.01 I-71 0.412 98.47 I-241 0.412 29.82 I-72 0.412 94.077 I-242 0.412 68.8 I-73 0.412 87.69 I-243 0.412 60.77 I-74 0.412 94.845 I-244 0.37 89.37 I-75 0.412 94.58 I-245 0.37 94.503 I-76 0.412 93.8 I-246 0.412 97.687 I-77 0.412 90.99 I-247 0.37 93.01 I-78 0.412 92.893 I-248 0.412 89.96 I-79 0.37 84.1 I-249 0.412 56.49 I-80 0.37 86.67 I-250 0.412 77.02 I-81 0.412 76.74 I-251 0.412 96.63 I-82 0.37 100.4 I-252 0.412 97.567 I-83 0.412 89.73 I-253 0.412 57.495 I-84 0.412 60.49 I-254 0.37 93.96 I-85 0.37 72.64 I-255 0.412 85.61 I-86 0.412 74.16 I-256 0.412 71.975 I-87 0.412 91.045 I-257 0.412 96.843 I-88 0.412 90.035 I-258 0.412 93.9 I-89 0.412 95.61 I-259 0.412 96.14 I-90 0.412 97.725 I-260 0.412 73.165 I-91 0.412 86.94 I-261 0.412 87.465 I-92 0.412 90.885 I-262 0.412 68.195 I-93 0.412 90.1 I-263 0.412 91.085 I-94 0.412 93.49 I-264 0.412 93.01 I-95 0.412 98.06 I-265 0.412 81.31 I-96 0.412 80.87 I-266 0.412 87.93 I-97 0.412 79.127 I-267 0.412 94.803 I-98 0.412 90.96 I-268 0.37 93.25 I-99 0.412 93.04 I-269 0.412 94.46 I-100 0.37 90.63 I-270 0.412 83.43 I-101 0.412 95.69 I-271 0.412 96.91 I-102 0.412 94.31 I-272 0.412 97.55 I-103 0.37 100.07 I-273 0.412 85.073 I-104 0.412 82.49 I-274 0.37 78.85 I-105 0.412 86.485 I-275 0.412 94.855 I-106 0.37 78.52 I-276 0.412 88.11 I-107 0.412 85.23 I-277 0.412 71.2 I-108 0.412 91.385 I-278 0.412 26.22 I-109 0.412 95.877 I-279 0.412 87.887 I-110 0.412 76.04 I-280 0.412 20.885 I-111 0.412 93.497 I-281 0.37 90.82 I-112 0.412 95.24 I-282 0.412 95.55 I-113 0.412 95.605 I-283 0.412 63.3 I-114 0.37 93.75 I-284 0.412 76.835 I-115 0.412 90.173 I-285 0.412 95.3 I-116 0.412 80.23 I-286 0.412 21.17 I-117 0.412 93.26 I-287 0.412 67.6 I-118 0.412 93.32 I-288 0.412 94.857 I-119 0.412 95.535 I-289 0.412 96.7 I-120 0.412 94.76 I-290 0.412 98.523 I-121 0.412 71.865 I-291 0.37 89.555 I-122 0.412 94.643 I-292 0.37 82.76 I-123 0.412 71.655 I-293 0.37 91.45 I-124 0.37 91.39 I-294 0.37 55.97 I-125 0.37 88.203 I-295 0.37 72.51 I-126 0.37 95.605 I-296 0.37 94.25 I-127 0.412 96.146 I-297 0.37 61.455 I-128 0.412 95.88 I-298 0.37 94.6 I-129 0.412 96.345 I-299 0.37 90.58 I-130 0.412 93.015 I-300 0.37 91.66 I-131 0.412 96.93 I-301 0.37 88.12 I-132 0.412 59.78 I-302 0.37 83.46 I-133 0.37 92.18 I-303 0.37 93.285 I-134 0.37 88.62 I-304 0.37 90.87 I-135 0.37 95.33 I-305 0.37 98.97 I-136 0.37 93.98 I-308 0.37 97.915 I-137 0.37 99.45 I-309 0.37 83.775 I-138 0.37 80.16 I-310 0.37 90.3 I-139 0.412 78.51 I-311 0.37 91.575 I-140 0.412 96.475 I-312 0.37 76.235 I-141 0.412 90.54 I-313 0.37 73.155 I-142 0.37 97.397 I-314 0.37 93.525 I-143 0.37 96.555 I-315 0.37 90.085 I-144 0.412 81.17 I-316 0.37 87.73 I-145 0.412 76.74 I-317 0.37 93.21 I-146 0.412 65.71 I-318 0.37 86.365 I-147 0.412 93.247 I-319 0.37 98.62 I-148 0.412 91.19 I-320 0.37 90.395 I-149 0.412 97.26 I-321 0.37 87.345 I-150 0.412 30.12 I-322 0.37 76.11 I-151 0.412 96.19 I-323 0.37 94.555 I-152 0.412 95.987 I-324 0.37 91.21 I-153 0.412 89.89 I-325 0.37 42.12 I-154 0.37 93.865 I-327 0.37 92.01 I-155 0.412 19.55 I-328 0.37 96.7 I-156 0.412 55.71 I-329 0.37 92.61 I-157 0.412 94.83 I-331 0.37 87.21 I-158 0.412 72.53 I-332 0.37 90.42 I-159 0.412 91.32 I-334 0.37 93.775 I-160 0.412 87.44 I-336 0.37 90.515 I-161 0.412 67.05 I-337 0.37 57.69 I-162 0.412 94.197 I-338 0.37 96.76 I-163 0.412 92.47 I-339 0.37 89.87 I-164 0.412 94.1 I-340 0.37 94.885 I-165 0.412 59.46 I-341 0.37 94.55 I-166 0.37 78.83 I-342 0.37 69.495 I-167 0.412 96.09 I-343 0.37 91.32 I-168 0.412 72.76 I-344 0.37 93.12 I-169 0.412 62.83 I-345 0.37 81.925 I-170 0.412 67.075 I-346 0.37 87.01 I-347 0.37 63.68 I-394 0.37 49.16 I-395 0.37 80.78 I-396 0.37 62.345 I-397 0.37 96.325 I-398 0.37 79.035 I-399 0.37 61.82 I-400 0.37 73.92 I-401 0.37 88.245 I-402 0.37 91.695 I-403 0.37 −4.605 I-404 0.37 5.79 I-405 0.37 91.99 I-406 0.37 86.59 I-407 0.37 51.145 I-408 0.37 94.94 I-409 0.37 92.51 I-410 0.37 68.09 I-411 0.37 85.115 I-412 0.37 92.965 I-413 0.37 94.145 I-414 0.37 95.38 I-415 0.37 79.905 I-416 0.37 90.0 I-417 0.37 56.745 I-418 0.37 29.545 I-419 0.37 23.22 I-420 0.37 85.315

As detailed above, compounds of the invention are selective for HDAC6 over other Class I HDAC enzymes. In some embodiments, the ratio of HDAC IC50 (as obtained in the nuclear extract assay described above) to HDAC6 IC50 is less than 5 (HDAC IC50/HDAC6 IC50). In certain embodiments, the ratio of HDAC IC50 to HDAC6 IC50 is between 5 and 10. In certain embodiments, the ratio of HDAC IC50 to HDAC6 IC50 is between 10 and 100.

While we have described a number of embodiments of this invention, it is apparent that our basic examples may be altered to provide other embodiments, which utilize the compounds and methods of this invention. Therefore, it will be appreciated that the scope of this invention is to be defined by the appended claims rather than by the specific embodiments, which have been represented by way of examples. 

1. A compound of formula (I):

or a pharmaceutically acceptable salt thereof; wherein: each occurrence of R¹ is independently hydrogen, chloro, fluoro, —O—C₁₋₄ alkyl, cyano, hydroxy, C₁₋₄ alkyl, or C₁₋₄ fluoroalkyl; one of R^(2a) and R^(2b) is R¹, and the other is —C(O)—NH—OH; X is C(R^(1c))(R^(1d)) or N—R^(b); R^(1d) is taken together with R^(1b) to form a double bond; R^(1C) is hydrogen, fluoro, bromo, —CH₂—OR^(4aa), —CH₂N(R^(4aa))₂, or C₁₋₄ alkyl; R^(b) is hydrogen, C₁₋₆ alkyl, benzyl, or phenyl; or R^(b) is taken together with R^(1b) to form a double bond; when X is C(R^(1c))(R^(1d)), R^(1b) is taken together with R^(1d) to form a double bond; and when X is N—R^(b), R^(1b) is taken together with R^(b) to form a double bond, or is taken together with R^(a) to form a double bond, or is taken together with R^(1a) to form C═O; R^(1a) is hydrogen, fluoro, C₁₋₄ alkyl, C₁₋₄ fluoroalkyl, or G¹; or when X is N—R^(b), R^(1a) can be taken together with R^(1b) to form C═O; R^(a) is hydrogen, C₁₋₄ alkyl, or G; or when X is N—R^(b), R^(1b) can be taken together with R^(a) to form a double bond; G is hydrogen, —R³, -L₁-R³, or -L₂-V₁—R³; G¹ is —NH₂, —R³, -L₁-R³, —V₂—R³, -L₁-V₂—R³, or —V₂-L₁-R³; V₁ is —O—, —N(R^(4a))—, —S—, —N(R^(4a))—C(O)—, —C(O)—N(R^(4a))—, —SO₂—N(R^(4a))—, —N(R^(4a))—SO₂—, —C(O)—, —SO₂—, or —N(R^(4a))—C(O)—N(R^(4a))—; V₂ is —O—, —N(R^(4a))—, —C(O)—N(R^(4a))—, —N(R^(4a))—C(O)—N(R^(4a))—, or —N(R^(4a))—C(O)—O—; L₁ is an unsubstituted or substituted C₁₋₄ alkylene chain; L₂ is an unsubstituted or substituted C₂₋₄ alkylene chain; each occurrence of R^(4aa) is independently hydrogen or C₁₋₄ alkyl; R³ is unsubstituted or substituted C₁₋₆ aliphatic, unsubstituted or substituted 3-10-membered cycloaliphatic, unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur; and each occurrence of R^(4a) is independently hydrogen, unsubstituted or substituted C₁₋₄ aliphatic, unsubstituted or substituted 3-10-membered cycloaliphatic, unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur.
 2. The compound of claim 1, wherein: R^(2a) is C(O)—NH—OH; R^(2b) is R¹; X is N—R^(b); R^(b) is taken together with R^(1b) to form a double bond; and R^(a) is G.
 3. The compound of claim 1, wherein: R^(2a) is C(O)—NH—OH; R^(2b) is R¹; X is C(R^(1c))(R^(1d)); R^(1d) is taken together with R^(1b) to form a double bond; R^(1c) is hydrogen; and R^(a) is G.
 4. The compound of claim 1, wherein: each occurrence of R¹ is independently hydrogen, chloro, fluoro, cyano, hydroxy, methoxy, ethoxy, trifluoromethyl, methyl, or ethyl.
 5. The compound of claim 1, wherein: each substitutable carbon chain atom in R³ is unsubstituted or substituted with 1-2 occurrences of —R^(5dd); each substitutable saturated ring carbon atom in R³ is unsubstituted or substituted with ═O, ═C(R⁵)₂, or —R^(5aa); each substitutable unsaturated ring carbon atom in R³ is unsubstituted or is substituted with —R^(5a); each substitutable ring nitrogen atom in R³ is unsubstituted or substituted with —R^(9b); each R^(5a) is independently halogen, —NO₂, —CN, —C(R⁵)═C(R⁵)₂, —C≡C—R⁵, —OR⁵, —SR⁶, —S(O)R⁶, —SO₂R⁶, —SO₂N(R⁴)₂, —N(R⁴)₂, —NR⁴C(O)R⁵, —NR⁴C(O)N(R⁴)₂, —NR⁴CO₂R⁶, —OC(O)N(R⁴)₂, —C(O)R⁶, —C(O)N(R⁴)₂, —N(R⁴)SO₂R⁶, —N(R⁴)SO₂N(R⁴)₂, unsubstituted or substituted C₁₋₆ aliphatic, unsubstituted or substituted 3-10-membered cycloaliphatic, unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur; or two adjacent R^(5a), taken together with the intervening ring atoms, form an unsubstituted or substituted fused 5-10 membered aromatic ring or an unsubstituted or substituted 4-10 membered non-aromatic ring having 0-3 heteroatoms independently selected from nitrogen, oxygen, and sulfur; each occurrence of R^(5aa) is independently chloro, fluoro, hydroxy, unsubstituted or substituted C₁₋₆ aliphatic, —O(C₁₋₆ alkyl), —C₁₋₆ fluoroalkyl, —O—C₁₋₆ fluoroalkyl, cyano, —N(R⁴)₂, —C(O)(C₁₋₆ alkyl), —CO₂H, —C(O)NH₂, —C(O)NH(C₁₋₆ alkyl), —C(O)N(C₁₋₆ alkyl)₂, —NHC(O)C₁₋₆ alkyl, —NHC(O)OC₁₋₆ alkyl, —NHC(O)NHC₁₋₆alkyl, or —NHS(O)₂C₁₋₆ alkyl; each occurrence of R^(5dd) is independently fluoro, hydroxy, —O(C₁₋₆ alkyl), cyano, —N(R⁴)₂, —C(O)(C₁₋₆ alkyl), —CO₂H, —C(O)NH₂, —C(O)NH(C₁₋₆ alkyl), —C(O)N(C₁₋₆ alkyl)₂, —NHC(O)C₁₋₆ alkyl, —NHC(O)OC₁₋₆ alkyl, —NHC(O)NHC₁₋₆alkyl, or —NHS(O)₂C₁₋₆ alkyl; each R⁴ is independently hydrogen, unsubstituted or substituted C₁₋₆ aliphatic, unsubstituted or substituted 3-10-membered cycloaliphatic, unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur; or two R⁴ on the same nitrogen atom, taken together with the nitrogen atom, form an unsubstituted or substituted 5- to 6-membered heteroaryl or an unsubstituted or substituted 4- to 8-membered heterocyclyl having, in addition to the nitrogen atom, 0-2 ring heteroatoms selected from nitrogen, oxygen, and sulfur; each R⁵ is independently hydrogen, unsubstituted or substituted C₁₋₆ aliphatic, unsubstituted or substituted 3-10-membered cycloaliphatic, unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur; each R⁶ is independently unsubstituted or substituted C₁₋₆ aliphatic, unsubstituted or substituted 3-10-membered cycloaliphatic, unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur; each R^(9b) is independently —C(O)R⁶, —C(O)N(R⁴)₂, —CO₂R⁶, —SO₂R⁶, —SO₂N(R⁴)₂, unsubstituted C₃₋₁₀ cycloaliphatic, C₃₋₁₀ cycloaliphatic substituted with 1-2 independent occurrences of R⁷ or R⁸, unsubstituted C₁₋₆ aliphatic, or C₁₋₆ aliphatic substituted with 1-2 independent occurrences of R⁷ or R⁸; each R⁷ is independently unsubstituted or substituted 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur, unsubstituted or substituted 6-10-membered aryl, or unsubstituted or substituted 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur; and each R⁸ is independently chloro, fluoro, —OR⁵, —CN, —N(R⁴)₂, —C(O)(C₁₋₆ alkyl), —CO₂H, —CO₂(C₁₋₆ alkyl), —C(O)NH₂, —C(O)NH(C₁₋₆ alkyl), or —C(O)N(C₁₋₆ alkyl)₂.
 6. The compound of claim 5, wherein: each substitutable saturated ring carbon atom in R³ is unsubstituted or substituted with —R^(5aa); the total number of R^(5a) and R^(5aa) substituents is p; p is 1-4; each R^(5a) is independently halogen, cyano, nitro, hydroxy, unsubstituted C₁₋₆ aliphatic, C₁₋₆ aliphatic substituted with 1-2 independent occurrences of R⁷ or R⁸, unsubstituted —O—C₁₋₆ alkyl, —O—C₁₋₆ alkyl substituted with 1-2 independent occurrences of R⁷ or R⁸, C₁₋₆ fluoroalkyl, —O—C₁₋₆ fluoroalkyl, —NHC(O)R⁶, —C(O)NH(R⁴), —NHC(O)O—C₁₋₆ alkyl, —NHC(O)NHC₁₋₆ alkyl, —NHS(O)₂C₁₋₆ alkyl, —NHC₁₋₆alkyl, —N(C₁₋₆ alkyl)₂, 3-10-membered cycloaliphatic substituted with 0-2 occurrences of —R^(7a), 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur substituted with 0-2 occurrences of —R^(7a), 6-10-membered aryl substituted with 0-2 occurrences of —R^(7a), or 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur substituted with 0-2 occurrences of —R^(7a); and each occurrence of R^(7a) is independently chloro, fluoro, C₁₋₆ aliphatic, C₁₋₆ fluoroalkyl, —O—C₁₋₆ alkyl, —O—C₁₋₆ fluoroalkyl, cyano, hydroxy, —CO₂H, —NHC(O)C₁₋₆ alkyl, —NH₂, —NHC₁₋₆ alkyl, —N(C₁₋₆ alkyl)₂, —C(O)NHC₁₋₆ alkyl, —C(O)N(C₁₋₆ alkyl)₂, —NHC(O)NHC₁₋₆ alkyl, —NHC(O)N(C₁₋₆ alkyl)₂, or —NHS(O)₂C₁₋₆ alkyl.
 7. The compound of claim 5, represented by formula (IV-a-i-a):

wherein: R^(1a′) is hydrogen, fluoro, or C₁₋₄ alkyl.
 8. The compound of claim 7, wherein: G is -L₁-R³, or -L₂-V₁—R³; and V₁ is —O— or —N(R^(4a))—.
 9. The compound of claim 8, wherein: each occurrence of R¹ is independently hydrogen, chloro, fluoro, cyano, hydroxy, methoxy, ethoxy, trifluoromethyl, methyl, or ethyl.
 10. The compound of claim 8, wherein: each substitutable saturated ring carbon atom in R³ is unsubstituted or substituted with —R^(5aa); the total number of R^(5a) and R^(5aa) substituents is p; p is 1-4; each R^(5a) is independently halogen, cyano, nitro, hydroxy, unsubstituted C₁₋₆ aliphatic, C₁₋₆ aliphatic substituted with 1-2 independent occurrences of R⁷ or R⁸, unsubstituted alkyl, —O—C₁₋₆ alkyl substituted with 1-2 independent occurrences of R⁷ or R⁸, C₁₋₆ fluoroalkyl, —O—C₁₋₆ fluoroalkyl, —NHC(O)R⁶, —C(O)NH(R⁴), —NHC(O)O—C₁₋₆ alkyl, —NHC(O)NHC₁₋₆ alkyl, —NHS(O)₂C₁₋₆ alkyl, —NHC₁₋₆ alkyl, —N(C₁₋₆ alkyl)₂, 3-10-membered cycloaliphatic substituted with 0-2 occurrences of —R^(7a), 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur substituted with 0-2 occurrences of —R^(7a), 6-10-membered aryl substituted with 0-2 occurrences of —R^(7a), or 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur substituted with 0-2 occurrences of —R^(7a); and each occurrence of R^(7a) is independently chloro, fluoro, C₁₋₆ aliphatic, C₁₋₆ fluoroalkyl, —O—C₁₋₆ alkyl, —O—C₁₋₆ fluoroalkyl, cyano, hydroxy, —CO₂H, —NHC(O)C₁₋₆ alkyl, —NH₂, —NHC₁₋₆ alkyl, —N(C₁₋₆ alkyl)₂, —C(O)NHC₁₋₆ alkyl, —C(O)N(C₁₋₆ alkyl)₂, —NHC(O)NHC₁₋₆ alkyl, —NHC(O)N(C₁₋₆ alkyl)₂, or —NHS(O)₂C₁₋₆ alkyl.
 11. The compound of claim 10, wherein: R^(1a′) is hydrogen; and R¹ is hydrogen.
 12. The compound of claim 5, represented by formula (IV-b-i-a):

wherein: R^(1a′) is hydrogen, fluoro, or C₁₋₄ alkyl.
 13. The compound of claim 12, wherein: G is -L₁-R³, or -L₂-V₁—R³; and V₁ is —O— or —N(R^(4a))—.
 14. The compound of claim 13, wherein: each occurrence of R¹ is independently hydrogen, chloro, fluoro, cyano, hydroxy, methoxy, ethoxy, trifluoromethyl, methyl, or ethyl.
 15. The compound of claim 13, wherein: each substitutable saturated ring carbon atom in R³ is unsubstituted or substituted with —R^(5aa); the total number of R^(5a) and R^(5aa) substituents is p; p is 1-4; each R^(5a) is independently halogen, cyano, nitro, hydroxy, unsubstituted C₁₋₆ aliphatic, C₁₋₆ aliphatic substituted with 1-2 independent occurrences of R⁷ or R⁸, unsubstituted alkyl, —O—C₁₋₆ alkyl substituted with 1-2 independent occurrences of R⁷ or R⁸, C₁₋₆ fluoroalkyl, —O—C₁₋₆ fluoroalkyl, —NHC(O)R⁶, —C(O)NH(R⁴), —NHC(O)O—C₁₋₆alkyl, —NHC(O)NHC₁₋₆ alkyl, —NHS(O)₂C₁₋₆ alkyl, —NHC₁₋₆ alkyl, —N(C₁₋₆ alkyl)₂, 3-10-membered cycloaliphatic substituted with 0-2 occurrences of —R^(7a), 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur substituted with 0-2 occurrences of —R^(7a), 6-10-membered aryl substituted with 0-2 occurrences of —R^(7a), or 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur substituted with 0-2 occurrences of —R^(7a); and each occurrence of R^(7a) is independently chloro, fluoro, C₁₋₆ aliphatic, C₁₋₆ fluoroalkyl, —O—C₁₋₆ alkyl, —O—C₁₋₆ fluoroalkyl, cyano, hydroxy, —CO₂H, —NHC(O)C₁₋₆ alkyl, —NH₂, —NHC₁₋₆ alkyl, —N(C₁₋₆ alkyl)₂, —C(O)NHC₁₋₆ alkyl, —C(O)N(C₁₋₆ alkyl)₂, —NHC(O)NHC₁₋₆ alkyl, —NHC(O)N(C₁₋₆alkyl)₂, or —NHS(O)₂C₁₋₆ alkyl.
 16. The compound of claim 15, wherein: R^(1a′) is hydrogen; and R¹ is hydrogen.
 17. The compound of claim 5, represented by formula (IV-b-ii-a):

wherein: R^(1a′) is hydrogen, fluoro, or C₁₋₄ alkyl.
 18. The compound of claim 17, wherein: G is -L₁-R³, or -L₂-V₁—R³; and V₁ is —O— or —N(R^(4a))—.
 19. The compound of claim 18, wherein: each occurrence of R¹ is independently hydrogen, chloro, fluoro, cyano, hydroxy, methoxy, ethoxy, trifluoromethyl, methyl, or ethyl.
 20. The compound of claim 18, wherein: each substitutable saturated ring carbon atom in R³ is unsubstituted or substituted with —R^(5aa); the total number of R^(5a) and R^(5aa) substituents is p; p is 1-4; each R^(5a) is independently halogen, cyano, nitro, hydroxy, unsubstituted C₁₋₆ aliphatic, C₁₋₆ aliphatic substituted with 1-2 independent occurrences of R⁷ or R⁸, unsubstituted —O—C₁₋₆ alkyl, —O—C₁₋₆ alkyl substituted with 1-2 independent occurrences of R⁷ or R⁸, C₁₋₆ fluoroalkyl, —O—C₁₋₆-fluoroalkyl, —NHC(O)R⁶, —C(O)NH(R⁴), —NHC(O)O—C₁₋₆ alkyl, —NHC(O)NHC₁₋₆ alkyl, —NHS(O)₂C₁₋₆ alkyl, —NHC₁₋₆ alkyl, —N(C₁₋₆alkyl)₂, 3-10-membered cycloaliphatic substituted with 0-2 occurrences of —R^(7a), 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur substituted with 0-2 occurrences of —R^(7a), 6-10-membered aryl substituted with 0-2 occurrences of —R^(7a), or 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur substituted with 0-2 occurrences of —R^(7a); and each occurrence of R^(7a) is independently chloro, fluoro, C₁₋₆ aliphatic, C₁₋₆ fluoroalkyl, —O—C₁₋₆ alkyl, —O—C₁₋₆ fluoroalkyl, cyano, hydroxy, —CO₂H, —NHC(O)C₁₋₆ alkyl, —NH₂, —NHC₁₋₆ alkyl, —N(C₁₋₆ alkyl)₂, —C(O)NHC₁₋₆ alkyl, —C(O)N(C₁₋₆ alkyl)₂, —NHC(O)NHC₁₋₆ alkyl, —NHC(O)N(C₁₋₆alkyl)₂, or —NHS(O)₂C₁₋₆ alkyl.
 21. The compound of claim 20, wherein: R^(1a′) is hydrogen; and R¹ is hydrogen.
 22. The compound of claim 5, represented by formula (IV-b-i-b):

wherein: R^(a′) is hydrogen, or C₁₋₄ alkyl.
 23. The compound of claim 22, wherein: G is —R³, or -L₁-R³.
 24. The compound of claim 23, wherein: each occurrence of R¹ is independently hydrogen, chloro, fluoro, cyano, hydroxy, methoxy, ethoxy, trifluoromethyl, methyl, or ethyl.
 25. The compound of claim 23, wherein: each substitutable saturated ring carbon atom in R³ is unsubstituted or substituted with —R^(5aa); the total number of R^(5a) and R^(5aa) substituents is p; p is 1-4; each R^(5a) is independently halogen, cyano, nitro, hydroxy, unsubstituted C₁₋₆ aliphatic, C₁₋₆ aliphatic substituted with 1-2 independent occurrences of R⁷ or R⁸, unsubstituted —O—C₁₋₆ alkyl, —O—C₁₋₆ alkyl substituted with 1-2 independent occurrences of R⁷ or R⁸, C₁₋₆ fluoroalkyl, —O—C₁₋₆ fluoroalkyl, —NHC(O)R⁶, —C(O)NH(R⁴), —NHC(O)O—C₁₋₆ alkyl, —NHC(O)NHC₁₋₆ alkyl, —NHS(O)₂C₁₋₆ alkyl, —NHC₁₋₆ alkyl, —N(C₁₋₆alkyl)₂, 3-10-membered cycloaliphatic substituted with 0-2 occurrences of —R^(7a), 4-10-membered heterocyclyl having 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur substituted with 0-2 occurrences of —R^(7a), 6-10-membered aryl substituted with 0-2 occurrences of —R^(7a), or 5-10-membered heteroaryl having 1-5 heteroatoms independently selected from nitrogen, oxygen, and sulfur substituted with 0-2 occurrences of —R^(7a); and each occurrence of R^(7a) is independently chloro, fluoro, C₁₋₆ aliphatic, C₁₋₆ fluoroalkyl, —O—C₁₋₆ alkyl, —O—C₁₋₆ fluoroalkyl, cyano, hydroxy, —CO₂H, —NHC(O)C₁₋₆ alkyl, —NH₂, —NHC₁₋₆ alkyl, —N(C₁₋₆ alkyl)₂, —C(O)NHC₁₋₆ alkyl, —C(O)N(C₁₋₆ alkyl)₂, —NHC(O)NHC₁₋₆ alkyl, —NHC(O)N(C₁₋₆alkyl)₂, or —NHS(O)₂C₁₋₆ alkyl.
 26. The compound of claim 25, wherein: R^(a′) is hydrogen; and R¹ is hydrogen.
 27. A pharmaceutical composition comprising a compound of claim 1 and a pharmaceutically acceptable carrier.
 28. A method of treating a proliferative disorder in a patient comprising administering to said patient a therapeutically effective amount of a compound of claim
 1. 29. The method of claim 28, wherein the proliferative disorder is breast cancer, lung cancer, ovarian cancer, multiple myeloma, acute myelogenous leukemia, or acute lymphoblastic leukemia.
 30. A method for inhibiting HDAC6 activity in a patient comprising administering a pharmaceutical composition comprising an amount of a compound of claim 1 effective to inhibit HDAC6 activity in the patient. 